Popo was a boy living with his mother in woods. One day, strange things happened, and that made his mother turn into a plantlike figure. She says, "Popo, please save food. You're the guardian of the woods". To cure her, he traced his father who had left home several years before leaving a message, "Every time the east forest shines, the world is going to be destroyed".

Suddenly, a large beetle with red eyes assaulted him. At the moment when he began to accept his death, a beetle named "Mushi King" saved him. When he felt relieved, a small beetle, "Chibi King" flied to his head, it seemed attached to him. This is how, the journey of Popo and Chibi King began.

Whether can Popo meet his father and turn his mother back?