When butterfly warriors suddenly descend on Yamabiko Village, they carry off Hana Kappa's mother and the other mothers of the village. Determined to bring them home, Hana Kappa sets out with his friends for the mysterious Butterfly Kingdom. The kids brave a frozen winter mountain and a scorching summer desert along the way, and they are joined by Poru, a puzzling boy who seems to be hiding a secret. Why the mothers were taken remains a mystery. The film is a lighthearted comedy adventure about friendship and family.