When Akito found out that his curse had been broken, she kept Kureno confined in her house for most of his life, and at one point, had a sexual affair with him to keep him there and for him to want her as a woman and not just as God. He is one of the only four Sohmas who knew all along that Akito was a female. He tells Tohru that the four who knew were Shigure, Hatori, Ayame, and himself. He also says that Ritsu had the same dream, but was "too young and didn't really understand".
Kureno is noted to be very much like Tohru: kind, polite, slightly scatterbrained at times, and cares more for others around him than for himself. Arisa describes him as the kind of person who can step in dog poo and not notice. When she is no longer able to see Kureno, she becomes very upset, and keeps thinking of him.
Kureno appears to be smaller than Shigure so he might be around 5'8 -5'9. He has auburn hair and reddish-brown eyes. He is two years younger than Hatori, Shigure, and Ayame, but he is also two years older than Ritsu, putting him around to be 26 years old.
Fruits Basket (Manga)
Uotani Arisa - who finds him "hot" - meets him in the convenience store she works at and is immediately attracted to him, and vice versa. Later, Arisa finds him while he's out, and the two go out to eat. Kureno tells her that he's content with his life, causing Arisa to lash out, shouting that his smiles should be happier. Kureno explains himself and almost kisses her. However, Kureno broke off their relationship, explaining to Tohru that he'd made a promise to Akito to stay by her side.
Kureno is the one who releases Isuzu from the cat compound after her imprisonment. After giving Akito some advice about her behavior, Akito stabs him angrily in the back, whereupon Kureno collapsed and was sent to the hospital. Arisa went to visit him there, and the two of them later moved out to live in the countryside together.
Kureno first met Arisa when he went to the store that she was working at, at the time. After they met, they could not stop thinking about each other. Arisa finally saw him walking by and talked with him. He took her out for a meal. Arisa and Kureno had a slow-moving relationship through the manga, but at the end of the manga, they move away to the country-side and live together.
Akito was Kureno's initial crush before Arisa. He used to spend a lot of time with Akito when they were kids and continued to do so as adults. The main reason why Kureno stayed with Akito was mainly pity, especially since his curse was broken before anyone else's. Unlike the rest of his family, Kureno suffers the least amount of violence from Akito. Even when Akito stabbed him, he forgave her and she went to get help for him.
- He doesn't appear in the anime.
all information on Sohma Kureno came from http://fruitsbasket.wikia.com/wiki/Kureno_Sohma