Kokushibo pursues strength and greatly desires to be the strongest, causing an inferiority complex towards his younger brother. At first, he thought of himself as superior and pitied Yoriichi, but after witnessing his strength he became jealous and began to hate his brother. Mysterious, composed, grim, serious and yet somewhat honorable, Kokushibo is a serious person who loves to fight, and never plays around. He is also the most loyal enforcer of the Upper Ranks of the Twelve Kizuki.