A boy stumbles into a dead city and accidentally rewrites everything, time collapses inward, and suddenly the war you're watching isn't the war you thought it was. The mecha fights earn their weight because they're not about saving the world; they're about saving one person, again and again, across a timeline that refuses to stay linear. Twelve episodes have no right to land this hard, but the story knows exactly what it's built for: the moment when you realize what he's actually been fighting for.

In AD 3567, humanity has lost its once great civilization and lives on in the ruins it left behind. Gardeners, mysterious unmanned mobile weapons of various ranks sent from the Moon, threaten people's lives, and brave teenagers take up work as Gardener hunters to earn a living. Thanks to maintenance-free high technology, parts of some surviving cities still function in limited ways and support the people who live in them. When Tokito Aizawa meets a girl named Tea, a power older than the Gardeners awakens, and it may open the way to a brighter future for what remains of mankind. The series is a mecha adventure with drama and romance.