A 30-something Gundam fan and engineer is forced to live with his recluse brother Maury and younger sister Lisa to take care of their Japanese grandmother after their mother's funeral.

On a quiet street in Helsinki, Sachie has opened a diner featuring rice balls. For a month she has no customers. Then, in short order, she has her first customer, meets Midori, a gangly Japanese tourist, and invites her to stay with her.