In the Edo Period, three enigmatic space capsules descended to earth, sparking fear of chaos among humans. Buried underground for safety, a descriptive map was entrusted to the Kamui family. Centuries later, these capsules begin to awaken. The first, Tri-Zenon, a Zenon Guardian, is now controlled by Akira Kamui, his brother Ai Kamui, and their friend Kanna. As aliens arrive with a mission, they must confront the awakened Tri-Zenon.