Keisuke Saji  

, 佐次 京介

Saji, a 16-year-old high school student with spiky hair, has an intense fascination with women and is determined to pursue a romantic relationship with the new arrival at school, Koizumi. Although unintentional or deliberate, Saji's actions towards Koizumi are inappropriate and have resulted in physical harm on multiple occasions. Despite this, Saji remains undeterred and continues to pursue his goal of sleeping with Koizumi.