Kana Sohma is an outside member of the Sohma family, and is, as such, not part of the The Chinese Zodiac. She is one of the first few "outsiders" to learn of the Zodiac curse. She appears in vol. 2 of the manga and episode 8 of the anime.
She is very friendly and caring towards those she loves. Kana hopes to be a successful doctor one day. She readily accepted Hatori Sohma after she discovered that he was possessed by the dragon. She is probably very protective, thinking herself to blame when Akito had hurt Hatori's eye. She is affected greatly by those around her.
Before Summer Vacation
Introduction of Hatori Sohma- the Dragon of the Zodiac
Not long after her memories are erased, Kana left the Sohma House to further pursue her career. In the manga, she married a young man not related to the Sohmas; her long-time best friend Mayuko Shiraki attended the wedding, but Hatori chose not to go, fearing that his presence would only cause trouble.
When Hatori meets Tohru, he asked her what snow turned into when it melted, and she answered, "Spring!" just like Kana, to Hatori's surprise. Also like Kana, when Tohru saw Hatori transform, she worried whether to put him in salt water or fresh.
Relationship with Hatori
Kana first met Hatori when she becomes his assistant and later his girlfriend. She once asked him when snow melts, what does it turn into. Hatori thought she was making fun of him and said water, but she exclaimed he was wrong and it turned into spring. One day, Hatori transformed into his zodiac animal and Kana realized why he never wanted to get close with people; still, she accepted him despite the curse. As he transformed into a seahorse, instead of being horrified or disgusted at how small he was, she started worrying whether to put him in fresh or salt water. She decided fresh, which Hatori tells her later could've killed a real seahorse the way that she had thrown him in a bathtub.
However, things took a turn for the worse when Hatori tells Akito that he and Kana wished to be married and asked for permission. Akito was angered that the relationship was beyond her knowledge, and that's when she injured Hatori's eye. Later, she shouted at Kana that everything was her fault; because of Akito's harsh words and the trauma derived of the incident itself, Kana began to truly believe that Hatori's injury really was her fault, despite the fact that it was beyond her control.
Over time, Kana's pain and guilt began to consume her, and she almost lost reason. Akito began to encourage Hatori to erase her memory, and Hatori finally agreed to do so; just before Hatori erased her memory, Kana apologized for not being able to protect him.