After a fatal plane crash claimed both parents, 16‑year‑old Ryuuichi Kashima is left to care for his younger brother Kotarou. While Ryuuichi maintains a warm, friendly demeanor, the toddler remains shy and too young to understand their loss. At their parents" funeral they meet Youko Morinomiya, the stern headmistress of a prestigious academy, who offers them shelter and school admission. In return Ryuuichi must become the academy"s babysitter. To support female teachers, the school established a babysitting club for their infants, but it is severely understaffed. Thus Ryuuichi must juggle caring for Kotarou and a handful of energetic toddlers, while navigating the demands of his new role on the bustling campus.
