Popo and his family live in harmony in a world surrounded by forest and insects until his father disappears, leaving him a mysterious necklace with magical powers. When his mother and the forest are attacked by the evil Passer, Popo decides to go in search of his father. When villains cross his path with giant beetles ready to attack him, Mushiking appears, the strongest beetle on the planet. Together, they will follow the path in search of Popo's father.