Kazu is proud of his reputation for strength and violence. This is made clear when he makes a beeping noise, which his friends recognize as Kazu turning on his switch to become his most aggressive. He has little sense of fair play, as he initiated the fight with Cain while Cain was turned away.
Kazu is tall with a very thickset body frame. He wears the sides of his light-colored hair in a short ponytail and lets the rest fall onto his neck.
When the four of them decide to approach Setsuka from behind, Kazu helps Kei flank her by taking her left side while Kei takes the right. When the four of them answer the question that Setsuka thought she'd asked Cain about apologizing, Kazu's contribution is to ask her what she thinks of a restaurant serving rice that isn't cooked correctly.
Kazu, known by his friends as the most brutal of the group, throws the first punch that starts the fight. It is aimed at the back of Cain's head.
Cain dodges the throw. This makes Kazu even more excited to fight. He attacks Cain again, but Cain continues to dodge every single punch. This doesn't stop Kazu from trying. Soon the rest of his group decide that Cain is doing this on purpose to wear Kazu down. They break out some collapsible beat sticks they'd kept hidden and go after Cain.
Kazu also is ready to change tactics to using a weapon. He aims a kick with his left foot at Cain's head, which Cain catches between his forearm and shoulder. It was a distraction technique, meant to make Cain not notice Kazu pulling a knife from his pocket with his right hand. Cain does notice though, and dodges, letting go of Kazu's foot, causing him to fall on the ground.
At the same moment Kyoko calls out a warning to Cain before one of the other guys can hit Ren from behind while he's focused on Kazu. She also tries to stop things from escalating by grabbing Kei's stick. Kei knocks her to the ground, angry at her attempt to interfere.
Having already dodged the attack of the beat sticks from behind by executing a cartwheel, Cain grabbed hold of Kazu's knife-arm when Kazu attacked Cain as he landed on his feet. When Ren sees that Kyoko's been knocked to the ground he goes berserk, in the original meaning of the word. His violence escalates, and in one move he changes the leverage of his hold on Kazu and flips him to the ground, knocking him unconscious.
Kazu remains unconscious through the rest of the fight and will afterward wake up with a concussion.
- (referring to fighting with Cain instead of spending time with Setsuka) ❝If I can't have the sister, the brother'll do just fine for me to play with!❞