A lonely little boy moves into a ramshackle apartment building all on his own and makes friends with the broke manga artist who lives next door.

One day, manga author Shin Karino is greeted by four-year-old Kotarou Satou, his new next-door neighbor, who gifts him a box of tissues. In Karino's eyes, Kotarou is an odd kid: he speaks in an extremely formal manner, and he lives alone in his apartment-no parents or relatives in sight. But Kotarou neither seems to mind, nor wants to rely on people. Feeling sympathetic toward Kotarou's circumstances, Karino decides to follow Kotarou to a bathhouse in case something might happen to him and there he comes to understand the little boy is not so different from him. Little by little, Karino-along with the other residents of the apartment complex-grows fond of Kotarou and his antics. At the same time, Kotarou himself might have found something akin to a family in his unique neighbors.—MAL Rewrite