In Kagoshima, der Junge Koichi lebt mit seiner Mutter Nozomi im Haus seiner Großeltern. Koichi vermisst seinen jüngeren Bruder Ryunosuke und seinen Vater Kenji, die in Fukuoka leben, und er träumt davon, dass seine Familie wieder zusammenkommt.
One day, Koichi overhears that the energy released by two bullet trains passing by each other would grant wishes and he invites his two best friends, Tasuku and Makoto, to travel to the point of intersection of the two trains.
Koichi also tells his plan to Ryunosuke that invites his three best friends to join him. Soon the seven children arrive to the meeting point in the journey of discoveries.