In a long-ago era when civilization had fallen to ruin, the tale unfolds. Hiyoko is a high schooler who harbors ambitions of joining an art college. Her father's attempt to dispose of her mother's treasured artwork drives her to escape her home. Drifting into a stadium-encased slum area, she crosses paths with Akira - the captain of a group of child vagrants. The stadium's inhabitants work towards rekindling the city's grandeur by dismantling the sports arena and establish an exhibition of street art known as "The Asylum Session." In the venture, Hiyoko oversees the painting on the stadium's grand wall and leads the charge.