Kayama is a male student at Shirakumo Academy who spearheads a trio engaged in bullying, extorting lunch money and smoking in restricted school zones. His confrontation with chemistry teacher Shino Sakurai over the smoking escalates when he flicks an object, knocking her down. Later, Kayama intrudes upon Shino Sakurai in her private residence, engaging in non-consensual sexual activity. The following day at school, he attempts to initiate another non-consensual encounter with her; the outcome of this attempt remains unspecified, though an unexpected consequence awaits him. His role is confined to these antagonistic actions.