During the Edo Period, three mysterious space capsules fell to Earth. Humans of that era, fearful of the chaos they might bring, buried the objects beneath the ground and entrusted a descriptive map to the Kamui family for safekeeping. Centuries later, the capsules begin to wake. The first — Tri-Zenon, one of the Zenon Guardians — is discovered on Bota Mountain by Kamui family descendants Akira and Ai and their friend Kanna. The other two, Gaia-zenoh and Arma-zenoh, emerge and join them. The alien fleet known as Zeno-Palace has arrived on Earth, and the three guardians are the only force capable of stopping them.