Kokushibo is a silent, very calm, reserved, aloof, mysterious, composed, grim, serious and somewhat honorable demon. He love to fight and ever play around. His real name when he was still a human is Michikatsu, only Yoriichi known and call him that. He still love his brother deeply although he killed Yoriichi himself. He is 480 years old. He's Loyal to Muzan. He had six, yellow eyes with red irises. He got the demon slayer mark despite after he turn into a demon he still had it.