The narrative unfolds in a distant future, after society has collapsed. Hiyoko, a high‑school student, dreams of enrolling at an art college. She flees home when her father attempts to discard her mother's treasured sketches. In a stadium‑shaped shantytown she encounters Akira, the leader of the street kids.
Police plan to tear down the stadium for urban renewal. To oppose this, residents organize a street‑art showcase titled "The Asylum Session." Hiyoko is tasked with creating a colossal mural on the stadium"s façade. The city"s skyline is dotted with towers, and the air smells of rust. Hiyoko vows to preserve her mother"s legacy through art.
