Kiro

KisaHiro is the het ship between Kisa Sohma and Hiro Sohma from the Fruits Basket fandom.

Canon
Kisa and Hiro are members of the Sohma family and grew up together. Having been best friends since their early childhood, they play and spend all their time together. During elementary school, Hiro developed romantic feelings for Kisa and told Akito -head of the Sohma family- about his feelings. This enraged Akito to where Kisa was beaten so severely that she had to be hospitalized for two weeks. Kisa was confused for what she could've done to provoke Akito and Hiro felt tremendous guilt and felt he couldn't tell Kisa the true reason for the beating. To protect Kisa from further abuse from Akito, Hiro began ignoring Kisa. Even when he learned she was being bullied at school, he couldn't bring himself to talk to and/or protect her.

Upon entering middle school, Hiro becomes jealous as Kisa becomes close to Tohru. He begins bullying Tohru in retaliation but when Kisa learns of this, she asks him to tell her why he is being mean to Tohru and when he does something bad, it makes her sad. He finally lashes out that he can't stand that all she cares about is Tohru and she never noticed that he was also worried about her when she was being bullied. This is enough to make her happy and forgive him.

After they watch an anime movie with Tohru at Shigure's house, they go to the park. Hiro feels guilty for not helping Kisa when she was injured by Akito and for being there for her when she was being bullied. He acknowledges that he is pretending to be tough in front of her but deep down he is just a kid. Because of this, he swears that he will become a real 'prince' and protect her. After buying cresps, Kisa notes how happy he looks.

They go to the Sohma beach house for summer vacation but end up having their first real fight. Hiro is again jealous at Kisa clinging to Tohru and begins asking Tohru why she is obsessed with her mother. This insensitive question upsets Kisa, who accuses him of coming on vacation to aggravate Tohru and she runs off. Hiro immediately regrets what he said and decides to talk to her. Coincidentally Kisa feels guilty for lashing out at him and decides to apologize. She goes to his room but he accidentally hits her face with the door as he's coming out. They both apologize for their actions and reconcile, with Hiro promising to be her prince.

Hiro and Kisa begin spending more and more time together. Due to having been forced to tell Haru about Rin being attacked by Akito, Hiro finally confesses to Kisa that he is the reason she was beaten before. He breaks down sobbing in guilt but she also starts crying and comforts him, saying it's not his fault.

They are invited to Shigure's house for dinner and think they are alone until Kyo comes home. As Kyo and Hiro argue, Kisa finally musters the courage to greet Kyo directly, rather than relying on Hiro to speak for her. This makes her very happy and Hiro is proud of her for overcoming her shyness.

After Hiro's curse broke, he asked Kisa if she hated him now that he wasn't one of the Zodiacs anymore. Kisa is momentarily surprised before asking him if he doesn't hate being with someone who's possessed as herself. However, before Hiro is able to confess his true feelings, they are interrupted by Kyo. When Hiro visits Akito for the first time after his curse broke, Kisa is the only one who follows him to act as a support for him, despite her fear of Akito.

Kisa is with Hiro when her curse breaks, shocking him as she begins crying. Some time later, they are walking together -her arms around his- as they discuss Tohru moving to the countryside with Kyo. Kisa starts crying and Hiro comforts her. Pulling her face closer to his, he encourages her to not stop showing her emotions and tears.

Fanon
KisaHiro is relatively popular within the Fruits Basket fandom due to that the two are childhood friends and their budding romantic feelings are too apparent.

This ship rivals with KisaToh, as Kisa adores Tohru and this often makes Hiro jealous.

Fandom
TUMBLR

Trivia

 * Kisa is a year older than Hiro.
 * In the Zodiac, the Tiger and the Sheep have a contented relationship, which is what Kisa and Hiro have.
 * KisaHiro is only couple not shown in the manga sequel Fruits Basket Another. As all the confirmed couples have gotten married, it's highly probable Kisa and Hiro did as well.