It's summer and nine-year-old Masao has no one to play with. With soccer practice suspended and his friends away at the beach, living alone with his grandmother seems even less fun. By chance, Masao discovers the address and photo of the mother he has never met. But with little money and even less sense of direction, he needs help. A friend of his grandmother volunteers her husband, Kikujiro, to accompany the boy on his quest. Kikujiro hardly seems an ideal companion for anyone, let alone for a boy as sensitive as the sullen Masao. Brash, loud-mouthed and always on the lookout for easy money, the irresponsible Kikujiro doesn't even appear to be overly fond of children. The first stop for the unlikely pair is to the cycle races, where Kikujiro gambles away the boy's travel money. In order to continue their journey, the two are forced to hitch rides, which they do with varying degrees of success. Ultimately, the two of them end up at a destination that neither of them could have imagined.