Kokushibo is reserved, silent, and aloof, maintaining an aura of unnerving tranquility and mystery that compliments his position as Upper Rank One. He rarely speaks; when he does, he talks in a slow and emphatic manner that gives more gravitas and authority to his words. He is an adamant rule-follower, punctual, and he shows a great deal of respect to the hierarchy of the Twelve Kizuki, as seen at the Upper Rank gathering. Kokushibo is shown to be humble as well. He serves under Muzan Kibutsuji.