Nishizaki is the leader of the Blacks. He is just as strong as Isshiki, but more violent. He was a soccer star until an injury ruined his knee. As his soccer career was over, Nishizaki has been a delinquent since middle school.
He is the son of Isshiki's father and his mistress. Once a month, he had to go dine with his father, and so he met Isshiki. At first he was glad to have a brother, but his feelings changed when his mother started comparing him with Isshiki. Isshiki's refusal to show any emotions is what bothers Nishizaki most about him. Thus he uses Hina to trigger reactions from Isshiki. There are also rumors saying that he's in love with Hina.