Some time before joining the Gotei 13, Komamura left his family, ashamed of living in the shadows. Although it is currently unknown where Komamura originated, Yamamoto gave him the opportunity to join the Gotei 13 even though he wasn't Human.
One day, while sitting on a grassy area, Komamura was sensed by Kaname Tosen, who didn't know where he was (due to his blindness). It was only when Komamura spoke that he realized he had talked in the wrong direction. Complimenting Komamura’s ability to hide his presence very well, Tosen noted that he had never been able to not feel someone’s presence before, even though his eyes cannot see. Komamura was highly touched, for this was the first time that he wasn't looked upon as an outcast.
Komamura met Tosen again during their time in the Gotei 13, and Aizen was introduced to Komamura through Tosen.
In contrast to his imposing physical stature, Komamura has a heart of gold, as well as being a loyal and grateful subordinate to Captain-Commander Genryusai Shigekuni Yamamoto, to whom he owes great gratitude for taking him in; so grateful that he would even die for him. The betrayal and subsequent departure of his close friend, Kaname Tosen, may have adversely affected his self-confidence and view of himself, since Tosen was the first person to have accepted him for who he is and not what he is. Sajin has also been shown to be a very forgivable person even if his friend is corrupt, or how evil they are, no matter how many innocent people they've killed, and even if they're about to kill him. This adverse effect is shown when he describes himself to Choe Neng Poww as "a meager worm" (he may have been speaking in sarcasm, however, as Poww previously referred to him and his opponents as "worms").
Komamura is also a very serious man, deeply scarred by the times when he was spurned by Soul Society for his appearance. He is not tough or cruel to his Division, preferring to lead them with impartiality. His favorite food is meat, but he dislikes carrots, supposedly because his father once told him that carrots were "not for their kind." Komamura tends to growl when angered. Despite being a gentle person, he is cold, ruthless and calculating when fighting. Once he is done fighting, however, he reverts to his gentle, giant self.
Komamura is pleased with Shuhei Hisagi's gift of a dog brush from the Human World, as he finds brushes in the Seireitei ineffective when grooming his fur. In addition, Iba imagines that Komamura will possibly use a dog Gigai if he were to go undercover in the Human World. He also likes dogs, especially ones of mixed breeds, and even keeps one, whose name is 'Goro', in his Division's quarters. During his free time, he takes Goro for strolls. He likes the Human World's puppy shows.
Komamura is an anthropomorphic wolf, although he is often mistaken for a dog. Initially, he was very self-conscious about his appearance, so he wore gloves with bracers, as well as a helmet, to conceal his entire body. However, he later gains enough confidence to go on without his helmet after Kaname Tosen's betrayal against Soul Society. He is the tallest captain of the Gotei 13. His fur is light-brown in color, which is the same color as his gloves. He also wears shoulder weights over his haori and large, plated boots instead of sandals. During the battle in the Fake Karakura Town, he wears a high collar, having a similar build to his shoulder weights, the top of which is visible in his uniform.
Later, during the second Wandenreich Invasion, he has received new armor. The new armor is more rounded at the shoulders than his old, and he has received a new helmet, and armor plating for his torso. When he utilizes his Human Transformation Technique, Komamura's appearance becomes closer to that of a Human, which retains his large size. He has long hair in this form, but he still retains his wolf ears and some fur on his forearms.
Komamura is highly proficient in swordsmanship, and is more than capable of holding his own against the likes of Kenpachi, who is arguably one of the most well-versed in swordsmanship as well as one of the greatest physical combatants in Soul Society.
Due to his large stature, Komamura has unbelievable physical strength. He was able to throw the Resurrección form of the giant Arrancar Choe Neng Poww, who was close to if not the same size as the giant his Bankai produces, and did so with apparent ease.
While not relying on the most advanced forms of unarmed combat, Komamura has shown great skill at brawling hand-to-hand fighting using his phenomenal strength to supplement his blows. This form of combat is what he excels in when not engaging in swordsmanship. He is skilled enough to go toe-to-toe with one of the foremost hand-to-hand combatants in Soul Society, Captain Sui-Feng.
Komamura is capable of taking considerable amounts of damage and still continuing to fight, despite the severity of his injuries. He refused medical treatment after being hit by Aizen's level 90 Kidō spell. He was also utterly unfazed from being punched across a great distance through parts of a city. He is durable enough to survive having his chest caved in and still continue to fight with no discernible handicap. Even after having his left hand severed by Aizen, he immediately counter-attacked, seeming to completely ignore the wound.
Because of his animal-likeness, he is seemingly in possession of superior senses.
Komamura has very keen reflexes in contrast to his large frame. He is capable of matching even the extremely fast attacks of Captain Sui-Feng.
It is also known that he is able to talk to animals.
Great Spiritual Power
As a Captain, Komamura possesses a great amount of spiritual energy. When Komamura releases his spiritual energy, it has the same magnitude of his enormous strength, and tends to destroy the area around him. He is quite skilled in hiding his spiritual presence because, due to his appearance, he does it quite frequently out of what he feels is a necessity to hide from others. He is able to use his spiritual pressure as a weapon, as he is capable of blasting back most normal enemies with a simple palm thrust without physically touching them, as seen when he incapacitated several unseated Shinigami soldiers who were controlled by the Bount Mabashi. His Reiatsu is red.
Komamura is highly proficient in Shunpo, with at least the average speed of a captain-level Shinigami.
Humanization Technique (人化の術, Jinka no Jutsu): A special technique that is unique to the werewolf clan that Komamura is from, which allows one to shed their beast form and return to their Human form. This is achieved by ritually removing one's heart. In this form, his body is nothing more then a shell. The secret technique of Human transformation allows his clan to obtain a immortal body by offering their physical heart. Therefore as long as he is Human he can never die. While in this state, attacks have no effect on either Komamura or his Bankai and all wounds quickly regenerate.
Tenken (天譴, "Heavenly Punishment"; Viz "Heavenly Retribution"): It takes the form of a normal katana. The cross-guard is a rectangle decorated with a pattern of vertical lines, with the long sides pinched in towards the middle. The overall appearance is similar to a squared-off hourglass.
Its Shikai command is "Roar" (轟け, Todoroke). Tenken maintains its form as a regular katana.
Shikai Special Ability
In its Shikai, Tenken creates various phantom body parts of a fearsome armored giant to copy whatever body part Komamura moves; for example, should Komamura swing his sword, a gigantic disembodied arm wielding a sword appears and mimics the movement. The body's gigantic parts generated by this Shikai possess strength and attacking power proportionate to their size (though not as great as it could be, due to not having a full body), making Komamura's Zanpakuto quite powerful.
Kokujo Tengen Myo'o (黒縄天譴明王, Vidyaraja of Kalasutra's Heavenly Punishment; Viz "Divine Retribution, Black Ropes of Ruination"): Komamura brings forth the entire giant, an armored Bankai with a life of its own. Standing at about a hundred meters tall, the giant resembles an armored samurai. It wields a sword with a guard similar to Komamura's, but with a different blade and a string hanging from the hilt. Komamura also retains its form as a regular katana. While in use, Komamura and his katana maintain a glow of spiritual energy.
Bankai Special Ability
The giant copies Komamura's movements to devastating effect, allowing it to deal out colossal amounts of damage. Its strength is proportionally far greater than that of Komamura, due to its size. It is strong enough to take a released Arrancar's point-blank Cero without being damaged, and could easily smother him with its bare hands.
It is also durable enough to withstand a blast from Captain Sui-Feng's "Jakuho Raikoben" while sustaining only a few injuries. Despite its enormous size, the giant is also deceptively fast, as it instantly copies all of Komamura's movements. However, his Bankai has a critical weakness. A powerful bond exists between Komamura and Kokujo Tengen Myo'o, causing any harm inflicted on the Bankai to be reflected onto its master. This essentially makes it a larger target to a sufficiently powerful opponent. However, this same bond allows Kokujo Tengen Myo'o to be restored if Komamura's wounds are healed, making it unique among Bankai. According to Tosen, it has such immense destructive power that Komamura has never considered that he might not defeat an enemy with a single strike, let alone receive a counterattack.
Dangai Joe (断鎧縄衣, Severed Mail and Thread-Clad): In its Dangai Joe form, Kokujo Tengen Myo'o's armor is removed, exposing a body composed of nothing but pure Reiatsu. Since its armor is its life, by shedding the armor, Kokujo Tengen Myo'o is literally casting its life aside. When Komamura uses this technique, his Bankai brings forth the entire giant as usual. The difference is that in this form, the giant sheds its armor and only has a large cord wrapped around its body multiple times. Its visage is exposed, appearing to be that of a demonic creature. This form is only possible via the use of Komamura's Humanization Technique. Due to the nature of the technique used to attain this form and its symbiotic connection with its wielder, this Bankai is virtually invulnerable to physical harm.
Soul Society arc
Komamura, standing between Captains Sosuke Aizen, and Kaname Tosen, attends a captain's emergency meeting regarding the questioning of Gin Ichimaru's apparent slip of duty in handling the Ryoka.
After Aizen’s apparent death, Komamura and Tōsen visit Aizen’s body in the 4th Division Relief Station. He still has not spoken at this point in time. On the day of Rukia Kuchiki's execution, his lieutenant, rushes to him and profusely apologizes for his lateness. Komamura interrupts him and says he knows that Iba understands that he needed time to think.
Later, Komamura, Iba, Tosen, and 9th Division Lieutenant Shuhei Hisagi stop Kenpachi Zaraki, and his men in an open courtyard from aiding the Ryoka. After an exchange of words, Komamura and Tōsen deal with Kenpachi while their lieutenants take on the 3rd and 5th Seats of the 11th Division. Komamura, getting tired of Kenpachi’s arrogance, unleashes his Shikai, while Tōsen follows up with his own, but neither are able to inflict more than superficial injuries. Kenpachi then sneers at Komamura and demands that he release his Bankai. Komamura is shown to be greatly angered by Kenpachi's words, and responds by telling him that he doesn't need it to fight a "traitor" like him. Tosen interrupts Komamura, informing him that he would release his first.
Although Kenpachi defeats Tosen, Komamura stops Kenpachi from killing his friend by deflecting Kenpachi's blade with his left arm and helmet. As a result, Komamura's helmet smashes into pieces and falls into the ground, revealing his true appearance: Komamura is a wolf. Komamura finally releases his Bankai to face Kenpachi and "satisfy" the latter's lust for fighting. However, sensing Yamamoto's Shikai, he later leaves Kenpachi to rush to his benefactor's aid.
Before reaching Yamamoto, Komamura hears the message of Aizen and Tosen's betrayal and rushes over to Sokyoku Hill to intercept the real traitors. Upon arriving at the hill, Komamura immediately attacks Aizen with his Shikai. But he quickly moves, and gets up close to Komamura. Then stops his blade with one hand. Aizen calmly mentions that it has been quite a while since he last saw Komamura’s face. Komamura gives a response of his own by angrily interrogating Aizen on how he can still smile, stating that he will never forgive him for betraying Soul Society. He again tries to strike him with his Shikai to which Aizen quickly moves out the way.
Angered at Aizen's treachery, Komamura then turns to Tosen. He demands an explanation for his own actions. Receiving no answer, Komamura attempts to release his Bankai. However, he is caught under the hypnosis of Aizen's Zanpakuto, leaving him vulnerable. Aizen takes advantage of this situation by performing a Level 90 Kido Spell on Komamura, easily defeating the 7th Division captain.
Komamura regains consciousness at the time of the three leaving, shouting for Tosen to get back down. "Why did you become a Shinigami?" he asks. "Was it not for your friend who died? Was it not for justice?" Tosen replies that he had told Komamura before that "all that is reflected in these eyes is the path of least blood. The path I walk is justice."
A week after the incident, Komamura visits the grave of Tosen’s friend, asking what the latter would have said to stop Tosen. Hisagi later joins and asks Komamura of Tosen's possible return. "Without a doubt," he replies. "By our own hands, let us open his eyes." He, along with Renji, Unohana, Rukia, and Ukitake, see Ichigo and his friends off when they return to the World of the Living.
Komamura is seen conversing with Lieutenant Shuhei Hisagi of the 9th Division, who explains to him about a unusual phenomenon of Shinigami attacking their own comrades, explaining its the doing of the Bount Mabashi and his doll. Komamura upon hearing this news asks if there is a way to break the control over those possessed, but Hisagi explains further that it's nearly impossible to remove the controlling doll unless they are dead. Later, Komamura is fighting alongside his division and Hisagi against the possessed Shinigami. He suggests that the possessed by moved to the 4th Division barracks as Captain Unohana would know what to do. He then is seen fighting of possessed Shinigami using his spiritual pressure to knock them out, until one actually stabs him with his sword, from there Komamura resolves to end the confrontation once and for all.
When Hitsugaya asks of the whereabouts of the other Gotei 13 captains, Isane informs him that Sajin has been assigned to guard Yamamoto from Kariya.
Zanpakuto Unknown Tales arc
Komamura is called by a Hell Butterfly to a emergency meeting by Captain-Commander Yamamoto, but upon arrival, the Captain- Commander is nowhere to be found. 1st Division lieutenant, Chōjirō Sasakibe, shows up injured and collapses. Then a mysterious figure appears, who announces that the Captain-Commander wont be showing up. Alarming everyone in attendance, upon hearing this. Komamura immediately gets in close to the stranger and begins to get angry, asking the stranger what has he done with Yamamoto. When the stranger doesn't answer, Komamura becomes even more enraged, and states he will then crush him. He takes out his Zanpakuto. The mysterious stranger moves out of the way and Komamura releases his Bankai, the stranger tells him that his powers won't work on him and when Komamura prepares for attack, Kokujo Tengen Myo'o instead attacks him.
Komamura moves at the last minute, but is greatly surprised, his Bankai then dissipates and he gets up to face another being, he is unsure at first who this new arrival is, but then he realizes it is Tenken; his Zanpakuto Spirit has materialized in its true form. Tenken then moves to attack, but Komamura blocks it. Eventually, the short fight ends with Tenken throwing ropes around Komamura, then, proving to be stronger than Komamura, drags him close and then deals a devastating blow to the captain, leaving him lying on the ground unconscious.
When the Shinigami were forced to retreat, Iba and Hisagi carry him off. He then undergoes medical treatment with the rest of the Shinigami injured by the renegade Zanpakuto at the 4th Division's medical facility. Later, he arrives in Karakura Town together with Tenken, and the other Zanpakuto and Shinigami. Still not quite fully recovered from his earlier injuries, Sajin sees this battle as a chance to get back in shape. He quickly unleashes his Bankai and begins slaying Gillians. Muramasa's Garaganta prevents the the number of Gillian from decreasing. Sajin and his allies turn their attention to the Garganta and use their combined Reiatsu to close it. Soon after, the Gillians are destroyed, and the dome collapses with Ichigo defeating Muramasa.
The New Captain Shunsuke Amagai arc
He is present at the promotion ceremony of the new captain of the 3rd Division, Shūsuke Amagai. Upon Amagai's arrival Komamura notes to himself that his Zanpakutō is a Kodachi. Komamura asks Shunsui Kyoraku, who he thinks observed his captain's proficiency exam, his opinion on the new captain.. Shunsui plainly states it doesn't really matter, as they should be happy that the Gotei 13 have one less position open. Sui-Feng interjects despite that Amagai will have to prove himself. Later that day, Komamura stands with Iba at the grave stone of Tosen's dead friend. He remarks that the 3rd Division is going to take action at the recent incident of Hollow incursion. He tells Iba that the Seireitei may be moving toward change, when Iba looks at him confused, Komamura explains that someone from one of the patrol units has suddenly become a new captain. He maintains that it has never happened before. Iba says that it may be true, but he wonders who the other two captains who tested him were. Komamura tells him he doesn't know, but he knows that something new is coming.
Komamura attends an emergency meeting with the remainder of the captains.
Fake Karakura Town arc
When Sosuke Aizen, Gin Ichimaru, Kaname Tosen, and Aizen's top three Espada leave to destroy Karakura Town, Komamura and the rest of the Gotei 13 captains currently not in Hueco Mundo await their arrival in a fake replicant of Karakura Town.
During the battles with Baraggan Louisenbairn's Fracción, he steps in to save Ikkaku Madarame after his defeat at the hands of Baraggan's largest Fracción, Choe Neng Poww. Komamura catches Poww off guard and punches him into the side of a building. Poww, however, is immediately back on his feet, unscathed, and is also unfazed by the captain being an animal. Poww then proceeds to punch him for several miles and releases his Zanpakuto. Komamura returns and stops an attack from the released Arrancar, who was attempting to attack his lieutenant and Ikkaku, and proceeds to throw the him over his head and in to the ground. Poww, unharmed, says the hit made him "yawn", which is actually him building up a Cero. Komamura then calmly releases his Bankai.
Poww fires the Cero, which Komamura's Bankai blocks with its sword. Poww proceeds to throw 4 punches, each of which is blocked. Komamura then proceeds to give Poww a punch of his own. After recovering, Poww proceeds to grapple with the giant, while simultaneously firing another Cero. This has seemingly no effect on it. The giant subsequently forces the Cero down Poww's own throat with his hand. The counterattack throws the Arrancar back and he falls to the ground. Komamura then kills Poww with a single blow from the giant's sword.
After Tetsuzaemon scolds Ikkaku for not using his Bankai, Komamura wiggles his ear, and Iba and Ikkaku immediately notices he was standing right next to them (again referencing the fact that he's great at hiding his spiritual pressure). Komamura says not to worry, and that it seems he has something in his ears. This possibly hints that he overheard Iba and Ikkaku's conversation about how Ikkaku can use Bankai, but he chooses not to reveal anything.
Some time after the battles against Baraggan's Fraccion, Komamura is seen along with the casualties while Izuru Kira attends to the injured lieutenants, possibly serving as a protector. He looks up at the sky, viewing the fights between the other captains and the Espada.
Seeing the huge Hollow creature come through the Garganta, Komamura notices its one eye and recalls seeing the same eye in the Garganta that opened when Aizen escaped Soul Society months before. He is suddenly brought out of thought by Kira, who tells them that he and the fallen lieutenants will be fine and that he should go as even if he stays and protects them, what would be the point if all the others died.
As Tosen sets himself to attack Shinji Hirako, he intersects the attack, Shinji asks if he should be helping them and Komamura just says that he is going to help and will not take no for an answer. Komamura then tells Tosen that he never thought he would be protecting someone from him. As Tosen tells him that their battle was inevitable, Shuhei Hisagi appears, and asks that he be allowed to fight as well.
Komamura stands with Shūhei in front of Tosen. When Tosen remarks that he will release his full power now that Aizen has joined the battle, Komamura believes Tosen means his Bankai, to which Komamura says he will release his as well. When Tosen retorts, however, saying that he has a power greater than Bankai, Komamura looks shocked as Tosen raises his hand to his face.
There is a release of spiritual pressure that Hisagi and Komamura shield themselves from, with Komamura yelling to Tosen, asking him what made him fall so low. When the smoke clears, Tosen stands before them with a Hollow mask, causing Hisagi to ask him if that is Hollowfication to which Tosen confirms. When Hisagi asks why, he is surprised as Tosen appears in front of him and slashes him, causing Komamura to release his Shikai. Tosen effortlessly blocks the attack much to Komamura's surprise, and is kicked to the side sending him crashing down into the town below. Tosen then comments to Komamura that it's ironic that the Gotei 13 ally with Ichigo, a Shinigami-Hollow hybrid just like him. He then asks Komamura to explain why his power has become despicable just because he has chosen to wield it.
Komamura explains that Ichigo Kurosaki did not choose to undergo Hollowfication. He, on the other hand as an elite Shinigami, had no need for such a thing, and chose it of his own free will. He then states that Tosen has been corrupted by that power. Tosen questions this explanation, and asks how flirting with his inner Hollow would prove anything of the sort. He states that Komamura only speaks in that tone because of his antiquated sense of dualism regarding Shinigami and Hollows. Komamura yells at him stating that is not what he meant, in fact referring to the way Tosen threw away his friends and subordinates simply to gain forbidden power. Komamura makes note that is where his corruption has led him astray.
Tosen goes to speak, but is cut off when a chain wraps around his neck, pulling him back and slamming him into the roof of a nearby building. He enters into a small conversation with Hisagi before he impales him on his blade and throws him off the side of the building. Tosen then states that his fear for the past 100 years is that he would assimilate with the rest of the Shinigami and die a pointless death. He is then interrupted as Komamura releases his Bankai.
Tosen scoffs at Komamura's Bankai as he releases it, saying that after the 7th Division captain had seen his power, fighting him with a mere Bankai is foolish. Tosen attacks the giant's right arm, injuring Komamura in the process. Komamura counterattacks and the giant's left arm hits Tosen several blocks away. This attack breaks Tosen's left arm, leaving it mangled. Tosen makes the observation that Komamura's Bankai is linked to his body and that injuring the giant corresponds to injuring Komamura. Tosen makes the comment that Komamura probably never considered the possibility of failing to defeat the enemy in a single strike or receiving a counterattack.
Tosen uses high-speed regeneration to fully restore his arm. Komamura tells Tōsen that he has truly abandoned his Shinigami nature. His reply is that those words are nothing more than excuses for his own defeat. Tosen repeats Komamura's words about him debasing himself, deceiving his friends in order to gain power. But then he asks Komamura "Joining an organization for the sake of revenge, yet in the course of one's peaceful life, they're forgetting that objective and serving that organization happily, would you not call that debasement?" As he speaks, his mask begins to crack and form a mouth.
Tosen then tells Komamura that the latter is more debasing than the former, shouting revenge. He asks Komamura if he thought it was strange "that a man whose greatest friend was killed would join the same organization as the killer?" Komamura answers that he thought his goal was justice, that he believed in his friend's ideals and wanted to fulfill them himself. Tosen says that Komamura is correct. Tosen states that justice is his goal, but asks what justice is, and that goodness and justice are not the same. He says that living out his peaceful life and not avenging his friend would be evil.
Komamura says that he had misjudged Tosen completely and that they will never meet eye-to-eye. Tosen ask if Komamura will strike him down, saying that it's laughable. Komamura replies if their core beliefs are incompatible, then attempting to use words is meaningless, saying that for the sake of Soul Society, he must strike Tosen down. He says to Tosen that he has already forgiven him in his heart. Tosen is slightly put off by this, telling him not to speak as though he were a god, saying that he had already forgiven him. Tosen tells him that he didn't ask for forgiveness and that if Komamura wanted to strike him down, he should do so if he is able to say that after witnessing his Resurreccion. Tosen then releases his Resurreccion: Suzumushi Hyakushiki, Grillar Grillo.
Tosen is enveloped in darkness and once it clears, he is shown to have transformed into a large winged bestial type creature. He opens his large eyes and comments that he can see Komamura. He becomes ecstatic yelling he can finally see and comments on seeing the sky, blood and the world. He tells Komamura that he is far uglier than he had imagined. He then rises up to attack his former friend, as he does, Tosen details that he fought for justice because of his friend and when he became a Shinigami that day, he pledged to follow her path. Komamura evades his attack and recalls that on that day he detected a small lie in Tosen's words.
Noting that Tosen spoke often of the world that she loved, but didn't once say a word about loving the world himself. Komamura admits that he understood this as anyone had the right to feel that way when a loved one was taken from him. He even respected that Tosen never acted like a saint and claimed he did love the world. Komamura had resolved that he would become a true friend to Tosen taking his sadness and giving him joy and being there for him as a true friend would.
He resolved to give Tosen back what he lost somehow. Komamura uses his Bankai, but Tosen is able to effortlessly stop the behemoth blade in his clawed hand damaging Komamura's Zanpakuto. As Komamura seems distracted by the chink in his blade Tosen draws circles in the air with his claws and uses his "Los Nueve Aspectos" technique, impacting Komamura's Bankai directly in the chest with tremendous crushing power, sending it crashing to the ground. Komamura falls, sustaining a similar injury to himself. Tosen comes over to Komamura and asks him if they should end the fight. He then says that justice is not something that can be expressed in mere words as he charges his Cero. Komamura then apologizes to Iba, Hisagi and Tosen, as he could not strike his former friend down.
As Tosen prepares to finish him off, they are both surprised as a blade goes through the top of Tosen's head. He then watches as Hisagi stands upon Tosen's back with his Zanpakuto impaled in his spine, which he then releases, impaling him further with one of the blades coming out of Tosen's mouth. When Tosen, who has returned to his normal form, regains consciousness. Komamura reminds Tosen about him saying that he knew the two would cross blades eventually, and that he too knew this would happen, as did Hisagi. He tells Tosen that he does not expect him to stop being angry, but that he should not focus only on vengeance until he loses himself. Sajin tells Kaname that like when he lost his friend, his heart would be empty if he lost Tosen. Kaname thanks him for his words and tells Hisagi that he wants to see his face, and that he can see in his Hollowfication form. Tosen explodes, splattering blood across the rubble. Komamura then yells at Aizen.
Just as Ichigo is about to break down by Aizen's words, Komamura steps in and warns him not to be taken in and lose himself, for he will lose his life as well. Komamura then reveals that everyone fighting in the Fake Karakura Town understood why the captains in Hueco Mundo sent him here. They all vow to fight, and protect Ichigo. Before joining the attack on Aizen, Sajin tells Ichigo that he is grateful to him for attacking Aizen at that moment, as he was about to attack Aizen himself, out of anger over Tosen.
He then joins Toshiro in fighting Aizen. When his Shikai proves ineffective against the renegade captain, Sajin releases his Bankai, but Aizen easily severs its blade. Then left arm at the middle of the forearm, and cutting the side of its torso, causing similar damage to Sajin, who screams in pain. Despite this, Sajin makes a final attack with his broken blade, but is blocked by Aizen, who then gives him a decisive blow to the chest which sends him hurtling down to the town below.
Gotei 13 Invasion Army arc
Sajin is present for a captain's meeting called by Yamamoto regarding disappearances in the Dangai. He listens to Mayuri's report that there is a time gap in the Dangai and his request to conduct a study to identify the cause. Some time later, Sajin accompanies a number of other captains and lieutenants to the Human World, which causes Kagerōza Inaba to retreat.
When Zaraki, Hitsugaya, Byakuya, and he head out to Soul Society through the Dangai, Komamura decides to use his Bankai to hold the current back. He is swallowed up by the current, trapping him in the Dangai. Komamura later arrives in Soul Society, interrupting a fight between Kenpachi and a Reigai of Sui-Feng. He apologizes for being late, saying that it took him a while to get through the Dangai. He takes Kenpachi's place in fighting the Reigai Sui-Feng (while ignoring Zaraki's protests). Kenpachi and Yachiru Kusajinshi leave, with the latter wishing him good luck. Komamura fights against Reigai Sui-Feng, their battle proceeding through the use of Shikai and hand-to-hand combat However, as the battle progresses, Komamura finds himself hopelessly outmatched against Reigai-Sui-Feng's Shunkō. He manages to reach a stalemate with her, resulting in both of them utilizing their Bankai. Komamura's Bankai proceeds to destroy Reigai-Sui-Feng's missile fired from her Bankai, resulting in her defeat. He then attempts to go and help out Yamamoto, but collapses from severe exhaustion. He is later healed and joins the other captains to aid Ichigo and Kisuke against their Reigai pursuers.
While the captains soon become overwhelmed by the Reigai's sheer power and numbers, the lieutenants later arrive and aid their respective captains. Sajin then unleashes his Bankai and joins his lieutenant in fighting their respective Reigai. Despite this assistance, the Reigai still pressure the Shinigami. Byakuya Kuchiki then realizes the truth behind the Reigai's battle style: they value self-preservation the most and won't attack first in fear of being outnumbered. Learning this, Sajin directly teams up with his lieutenant, voicing that such tactics won't defeat them.
Later, the resurrected Oko Yushima begins his endgame, using his Renzan: Hajo Kuri technique to begin destroying the Soul Society. Sajin realizes from the Reigai's expression that they weren't expecting this to happen. Before the Shinigami can act, the Reigai step forward, saying that they will stop their fellow Mod Soul's chaotic plan, as their goal has always been to protect the Soul Society in their own way. The Reigai then destroy the technique at the cost of their own lives.
The Lost Substitute Shinigami arc
Komamura is present when Kisuke Urahara explains to the Gotei 13 captains about his intentions to restore Ichigo Kurosaki's power. Yamamoto tells him to bring him the sword, which Urahara will do so. Then orders the captains, and lieutenants to put their Reiatsu into the sword. When Ichigo arrives in Soul Society to seek the return of Kugo Ginjo's body. Komamura is among the captains present to hear Ichigo's request, which he is surprised about.
The 10 Thousand Year Blood War arc
Komamura is present among the other captains when Mayuri explains the situation, and Yamamoto commands the captains to prepare for war. When the Sternritter invade Seireitei, he along with his lieutenant head out to deal with the invaders. Soon after heading out, he intercepts Bambietta Basterbine's Shinigami slaughter, commenting on his surprise that there's even a girl in the rebel army, while she comments that if a dog is a captain, Soul Society must be short on soldiers. With Iba backing him up, Komamura unleashes his Bankai to try to find a way to stop the Wandenreich from sealing their Bankai, Kokujo Tengen Myo'o, which is then instead stolen by Basterbine's Medallion. Komamura is shocked to find that his Bankai was stolen.
Later, Komamura is notified via transmitter swords along with the other captains and lieutenants by Rin Tsubokura that Ichigo is currently heading to Soul Society. When he senses that Yamamoto is moving onto the battlefield, he lets out a roar. He then tells the fallen members of his division to stand up, as it is shameful to lay down while the Captain-Commander is standing and raises their morale. Komamura and other captains are then later shocked to sense that Yamamoto had actually died at the hands of Yhwach. During the aftermath of the battle, Komamura and the other captains mourn the death of the Captain-Commander.
He remains silent after hearing Ukitake tell them that Yamamoto's body could not be found because the enemy likely destroyed it. Seeing Suì-Fēng break down at the news of Byakuya and Kenpachi, he yells at her to remind her that she isn't the only one feeling the pain of losing somebody. Before their infighting goes any further, Shunsui comes in to calm everyone down. He is then reminded by Shunsui that instead of mourning the dead, they should instead look to the future, and protect Soul Society. Because protecting Soul Society is the Gotei 13's purpose.
Komamura and the other captains later gather outside Seireitei to witness the arrival of the Royal Guard. Later, Komamura goes to a cave outside of Seireitei. He leaves his lieutenant outside and ventures in to the deep cave. Inside, he greets a giant dog, stating that it has been a long time. The creature recognizes him, and says that Komamura has guts to come back to the cave. Komamura addresses the creature as his great-grandfather, and states that he wants to learn the family secrets. After being rebuked for hiding his face, he states that society has changed in a way that he no longer has to hide, and that that society is now on the verge of crisis. His great-grandfather states that the world's bearers are the ones changing and that they should lay low. Komamura presses on with his goals, which prompts his great grand-father to say he has to crush him. Komamura sees his resolve and prepares to battle him.
After the fight, Komamura discusses the Humanization Technique with his great-grandfather. His great-grandfather explained that their werewolf clan were originally cursed to dwell in the Beast Realm due to their sins in life. Unable to accept their fate, they returned to Soul Society in their beast-like state. He further elaborated that the Human Transformation Technique is performed by momentarily removing the chains that bind them, recovering the forms they once held before they were cursed to live as beasts, and obtaining great power in the process. Komamura then asked how he can learn the technique, and his grandfather answered that he had to rip out his own heart. Komamura hesitated, but explained that he couldn't stand living in the shadows, which caused him to abandon his clan. Yamamoto took him in, and because of that, he is in debt to him. However, as Yamamoto was killed by the Quincy, Komamura became determined to clear away that shame and tears out his heart for his great-grandfather.
He later appears before Bambietta Basterbine as she is engaging in a temper tantrum after being left alone by her fellow Sternritter. Though he had regained his Bankai, he still confronts her clad in a newly gifted armor. While she comments that it doesn't matter and she will remove it after she defeats him, she admonishes him for arriving so fast before she could destroy some of the Seireitei as it would have been more dramatic. They are interrupted by Captain Shinji Hirako, but before they can engage her they witness her and the other Sternritter activating their Quincy: Vollstandig. He watches as Bambietta emerges in her Quincy: Vollständig form, and expresses shock upon witnessing her attacking Shinji.
Frustrated by Shinji's Shikai, Bambietta attacks in all directions, heavily wounding Shinji. Distraught over Shinji, Momo Hinamori attempts to attack Bambietta, but Komamura stops her and shields her from Bambietta's attacks, knowing that Momo isn't strong enough to endure the Quincy's attacks. Komamura tries to deflect Bambietta's explosions; however, Komamura learns that Bambietta causes explosions by firing her Reishi into objects, turning them into bombs. Bambietta continues to attack Komamura, completely destroying his armor, revealing that he has been transformed into a human.
Facing Bambietta calmly, Komamura activates his Bankai, Kokujo Tengen Myo'o Dangai Joe. Bambietta states that she is shocked that underneath the armor of his Bankai wasn't something that looked like a dog, but thinks maybe the dog is underneath the monster-like face. She launches her Reiatsu, but Kokujo Tengen Myo'o blocks it with its hand and she gazes in amazement as the explosion dissipates. Komamura explains to her how his Bankai has changed, but she continues to attack it with explosions to no avail.
Regardless of his explanation, Bambietta still doesn't understand what he means and states that Bankai have no life and that she, having possession of it his until recently, knows the all about his symbiotic connection to it and makes use of the weakness by exploding a hole in Kokujo Tengen Myo'o'. The hole is reflected on Komamura but he is unfazed by the injury much to her surprise. He tells her that as long as he is human he is immortal. She becomes irate, stating that throwing your life away is pointless if you're already dead, thus removing the point of winning. He corrects her and states that he didn't throw his life away; he placed it at stake just as Yamamoto had done and that he already left his life behind when he stepped into the fight in the first place. He then attacks her using his Bankai.
Bambietta is hit dead on with such power that it forces her explosions back onto her body, severely wounding her and causing her charred body to fall into the debris of buildings some distance away. Komamura then sets his sights on the Wandenreich Palace and attempts to move toward it. His Bankai begins to loose cohesion as his Humanfication technique begins to wear off. He tries to hold on as he begins to revert back from his human form in to a wolf, while swearing vengeance upon Yhwach. As he transforms, he realizes that it is the price he must pay for revenge, something his clan was made and reflects on his choice and what it has cost him. He then is picked up by his lieutenant, who tells him that he is not wrong and they will fight and beat Yhwach for Genryusai Shigekuni Yamamoto.
Sajin Komamura appears in the following video games:
- Bleach Dark Souls
- Bleach Soul Resurreccion
- Bleach The 3rd Phantom
- (To Tetsuzaemon Iba) "Don't worry. I have no doubts. My loyalty lies only in my debt to Genryūsai-sama. He took me in when I was alone because people pushed me away due to my looks. I shall repay this debt, even if it means I will be shattered into pieces. I shall have no doubts. If his greatness says ‘yes’, then even in death, I say ‘yes’!"
- (To Shuhei Hisagi) "...With our hands, we will open Tōsen's eyes!"
- (To Choe Neng Poww) "You're right. I have not yet introduced myself. I am Seventh Division Captain Sajin Komamura. And though it shames me, I am just as you say...a mere worm of a man."
- (To Kaname Tosen) "I never thought the day would come when I would be forced to protect someone from your blade."
- (To Tosen) "Ichigo Kurosaki did not seek that Hollow transformation of his own volition. But you are different. You chose that forbidden path for yourself, despite already possessing more than sufficient power as a Shinigami! You have debased yourself, Tosen!"
- (To Tosen) "It is your betrayal of your allies, betrayal of your friends, betrayal of your own subordinates - all for the purpose of obtaining this unnatural power that I refer to as debasement!"
- (To Tosen) "If our core beliefs are truly incompatible, then attempting to solve this with words is meaningless. For the sake of Soul Society, I must strike you down. I do not wish to do so. Having heard your true beliefs, I am now satisfied. In my heart, I have already forgiven you."
- (Referring to Tosen) "That is why I swore to myself that I would become a true friend to you. If you bore great sadness, I would take it upon myself. If I obtained great joy, I would share it with you. If you strayed from your path, I would scold you. If you made terrible mistakes, I would forgive you. If the world scorned you, I would be your shelter. Somehow, I would give this man who had lost his love for the world the power to love it once more."
- (To his great-grandfather) "When I was unable to bear the burden of living in shadow...When I abandoned my own family and fled, not caring for the shame I brought upon myself...It was Genryūsai-dono who took me in. That man, to whom I owe the greatest debt, has had his own life cut short at the hands of these Quincy. I have a duty...to avenge this humiliation!!"
- (To Bambietta Basterbine) "I have not thrown my life away. I have merely gambled it. Genryūsai-dono gambled his own life on this battle. I see no reason why I should not do the same. From the moment I set foot on this battlefield, I had already left my life behind!"
- As of the current Bleach character popularity poll (2009), he is ranked 36th.
- His Shikai command has yet to be used in the actual series. It has only been mentioned in Databooks and video games.
- In the Zanpakuto poll, Komamura's Bankai ranked equal 46th with 5 others, while his Shikai ranked equal 56th with 7 others.
- Kokujo Tengen Myo'o's skin, along with part of its helm, was of a different color in the anime in comparison with the manga (being orange and not gray), as its original color wasn't shown until Chapter 328. However this is later fixed in Episode 220 when Komamura summoned his Bankai against Poww.
- He is the author of A Puppy's Feeling and A Kitten's Feeling that appear in the Seireitei Communication.
- Japanese : Tetsu Inada
- English : Kim Strauss (Ep. 51 - 63), J.B Blanc (Ep. 64 - Present)
all information on Sajin Komamura came from http://bleach.wikia.com/wiki/Sajin_Komamura