Katsuki is a hard person to talk to. He rather look around and take in his surroundings than hold a conversation with someone. He's normally a laid back person until he's insulted in any way or if his values are belittled. He doesn't like to conform to hard cold facts because he lets his own feelings and knowledge be the judge of a situation. Around people he likes or is used to and trusts, he’s usually a lot more open and friendly, his face more lively and he’ll usually be smiling.