Kaito Shinonome

About

Kaito has a strong sense of justice and hates corrupt things, but tends to pick fights and prefers to go about his business alone as he doesn't like to rely on others. Kaito cares deeply for his sister, worrying for her all the time, but they often misunderstand each other because Kaito is clumsy at expressing himself.

Kaito's obsession with protecting Miu becomes even stronger whilst in the alternate World, leading him to become violent and hurt those around him. This obsession also annoys Miu and causes her to rebel against him. Dracmon helps Kaito calm down and think carefully before he acts.

If Takuma asks Kaito why he likes Miu so much, he will go on a long tangent in which he states he loves her physical appearance due to her being so cute and small, loves her cute eyes and the way she looks at him, the way she eats with her small mouth, and how slender her arms are with that making him wanna protect her. This freaks Takuma out, with him coming to the conclusion that his affection for his sister is incestual —though Kaito angrily relents that isn't the case and claims his affection for her is normal for a brother.



In the harmonious route, Kaito turns on the others with his mental state taking a turn for the worst after losing Miu. His desire for revenge sees him decide to kill not only every single Kemonogami, but the other children as well — blaming them all for what happened to her. Deep down he blames himself more, feeling he was too weak to protect her, but still sets out on his bloodthirsty path for revenge. Dracmon tries his best to stop him but to no avail, and simply supports his destined partner despite knowing he was doing the wrong thing. His thirst for revenge goes so far that he even teams up with Piedmon and decides to destroy not just the alternate world, but the human world as well, claiming it would be avenging Miu by doing so. He forces Dracmon to fuse with Piedmon, knowing full well that doing so would result in Dracmon no longer existing with the new entity, Boltboutamon, having a mind of its own rather than retaining Dracmon's (or Piedmon's). Dracmon didn't want to do it, but went along with it as Kaito's heart showed that he truly wanted it to happen leaving Dracmon no choice but to listen to him despite it essentially causing his own death. The children are eventually able to get through to him and have him move on from losing her with Kaito deciding to defend the world she loved so much.
(Source: Digimon Wiki)