In a class led by the fresh teacher Yabe Satoshi, the Marui triplets stand out for their striking differences. Mitsuba, the eldest, exudes a mature and sadistic aura. Futaba, the middle child, surprises with her athleticism and perversion, matching the strength of a grown man. Meanwhile, the youngest, Hitoha, appears quiet and gentle, yet harbors hidden depths of strength, perversion, and sadism. Despite their unique traits, the triplets band together to meddle in Yabe's love life, urging him towards the school nurse, Kuriyama Aiko. Unwilling to comply, Yabe faces an uphill battle against the triplets' unconventional tactics in this comedic tale of school dynamics.