Kotaro was always his usual emotionless self, until the class trial happened and Frimomen was the killer of Kisaragi Tsuina, the ultimate ogre hunter

Kotaro: WHY?! WHY DID YOU KILL TSUINA?! he was crying and holding on to Frimomen like the gay person that he is

(I ship Kotaro Kobayashi with Frimomen, literally)