In Okinawa, skaters gather after midnight at 'S,' a no-rules downhill race through an abandoned mine. Reki Kyan, a passionate but middling skater, brings his new Canadian classmate Langa Hasegawa to spectate, and Langa ends up on a board, his years of snowboarding translating into raw, instinctive talent. Their rising profile at 'S' draws the attention of ADAM, a politician by day who dominates the course with a reckless, violent skating style that has left opponents hospitalized.