コタローは1人暮らし

Kotaro Sato, a four-year-old who carries a toy sword and talks like the feudal lord from his favorite show, Tonosaman, moves by himself into apartment 203 of the run-down Shimizu Apartments. His next-door neighbor, the broke manga artist Shin Karino, ends up keeping an eye on the boy, as do other tenants with troubles of their own. Kotaro enrolls himself in kindergarten and handles daily life alone, and only slowly does it come out why a child his age is living without parents.