A girl dreaming of giant machines while her father tinkers in the garage below, neither knowing the dreams are real. The movie folds a father-daughter story and a sci-fi war into one fever dream, then makes you believe both at once. By the end, the machines stop mattering. What matters is that she finally understands what he was building all along.

Kokone Morikawa, a high school student in Kurashiki City, Okayama Prefecture, is supposed to be studying for her university entrance exams, but she keeps dozing off. Every nap pulls her into the same dream, where she is a princess of Heartland, a machine-driven future in which artificial intelligence is banned and machines wage war. Her father, a gifted mechanic, spends his time customizing motorcycles and cars. Three days before the 2020 Tokyo Olympics, the police suddenly arrest him. Kokone cannot believe he has done anything wrong, and she comes to see that her dreams hold the key to her family's hidden past and to clearing his name. As the dream world and the real one grow harder to tell apart, she must guard the secret her father tried to keep from her against threats from both sides. The film mixes action, drama, fantasy and mecha.