Masaru Kaneda reigns as the self-proclaimed bully of Class 5-3 at Dōmori Elementary, wielding intimidation to dominate vulnerable peers like Makoto. His authority fractures at the slightest misstep—when classmates twist his name into “Kintama Saru,” a crude jab meaning “testicle monkey,” sparking volatile outbursts. Though he prowls the school alone, two faceless lackeys occasionally trail him, amplifying his schemes. Yet his reign teeters on instability: Hiroshi, a defiant classmate, dismantles his tactics through direct intervention, while unseen forces retaliate when Masaru’s cruelty disturbs nearby yōkai. These supernatural interferences and human defiance ensure his plans crumble, cementing his role as a persistent but thwarted antagonist within the classroom’s fragile hierarchy.