A biomechanical alien and a traumatized girl become each other's reason to keep living, and the show does not blink away from what that costs them. The first half drags through repetitive cycles that feel like filler until you realize the show was building something the whole time, teaching you to trust the same way its characters learn to trust each other. By the finale, every small moment of connection between Frank and Hattie has become the entire point. The animation holds this fragile intimacy in close detail. This is mecha that forgot about the machines and remembered why we care about the people inside them.

In 2059, Earth has endured attacks by giant aliens for several years. Dr. Noguchi and his assistants, Maki Agata and Takuto Kaneshiro, try to revive the professor's experiment, a huge biomechanical alien called Frank. The creature awakens, the lab is destroyed, and Frank disappears into the wilderness, leaving Takuto as the only survivor. Out in the wilds, Frank meets Hattie, a troubled girl who lost her parents in the first war with the aliens and who can somehow communicate with it. The pair are soon taken into custody by a secret agency called Funeral. Takuto wakes in a hospital, disfigured and with his life in ruins. Driven by grief and a thirst for revenge, he takes an offer from the mysterious Mr. X and becomes Ryu Soma, a ranking Funeral officer. Mecha action and sci-fi drama frame his search for the truth behind the invasion.