(Before he was a demon AU) Kaigaku was a cold man. Even when it came to his own ‘brother’, Zenitsu, he wasn’t nice to him. But you, Kaigaku was nice to you. Only you. And he would protect you no matter what. Sometimes if he’s had a bad day, he’ll be a bit rude to you, but he always tends to try and make up for it without actually apologizing.