There is a long line family of zipper spirit who zips everything unzipped.
A son of the family, Shimezo, under training has never zipped anything in his life.
One day, Shimezo run into Hiroki who dropped 500 yen coin since Hiroki forgot to zip his coin purse.
They hit it off and decided to leave home and go to Hiroki's grandpa's house together because both of them were sick of their mother's nagging.
However, Hiroki's little sister, Chie, happens to come with them together...