Sousuke is a student at Kunugigaoka Junior High School and belongs to Class 3-E, where he receives training to become an assassin. His teacher serves as his target. Despite being highly skilled in drawing and sculpting, ranging from posters to disguise masks, Sousuke exhibits individualistic tendencies and engages in unpredictable attacks against Korosensei, the Anti-Sensei. For instance, he proposes drawing a Henna tattoo on Korosensei but secretly replaces the Anti-Sensei bullets with grounded powder mixed into the Henna paint.