Hatsuzu

Hatsuzu is the het ship between Hatsuharu Sohma and Isuzu Sohma from the Fruits Basket fandom.

Canon
Rin and Hatsuharu have a romantic and sexual relationship that began before the start of the series. When Akito finds out about it, Rin claims full responsibility to protect Hatsuharu, and to punish her Akito pushes Rin out a window; while recuperating in the hospital, Rin breaks up with Hatsuharu both to protect him and to avoid burdening him, but without explaining why.

To free Hatsuharu, Rin starts searching for a way to break the curse, and asks Kazuma, Shigure, and Ren Sohma for help, though she resists the assistance of Tohru Honda, who she thinks is too nice for her own good. Ren offers to help if Rin steals a treasure (a black box) from Akito, but Rin is caught by Akito, who confines her in the cat's prison and cuts off her hair; after she is released by Kureno, she reconciles with Hatsuharu, accepting his support. She also accepts Tohru's assistance because of the latter's kindness and grows as protective of her as of Hatsuharu, getting angry when someone upsets or hurts her.

Children
Sora Sohma

Sora is the only daughter of Haru and Isuzu. She has black hair from her mother.

Riku Sohma

Riku is the only son of Haru and Isuzu. He has white hair from his father.