A bunch of kindergarteners in Tokyo are just days away from graduating. Suddenly, five of them are nowhere to be found. They have set out to visit their friend who got confined to a hospital way out in the suburbs.

The parents and teachers are worried sick but the kids do not have a care in the world. Hopping from train to train, they have established one rule: no matter what happens, nobody is allowed to cry. Little did they know that troubles would be abound as they head towards an unknown land.