There is an honorable family of zipper youkai who will close any zipper if they happen to find it open. Their son Chuck Shimezou is currently in training, but has so far not yet closed a single zipper. One day, he gets to know a boy named Hiroki, who forgot to close the zipper on his coin purse and lost 500 yen. They bond over talk of their nagging mothers. Together, they run away from home, and head to Hiroki's grandfather's place, but they are also stuck with Hiroki's sister Chie.