The 8th game in ZUN's line of danmaku shmup games. Like other games in the series, players have characters with small hitboxes but are faced with screens filled with beatiful bullet patterns.

The game takes place in the mystic oriental land of Gensokyo. Someone has replaced the real moon with a fake moon that can never become full. Playing as one of 4 human/youkai teams, you must battle your way through 6 difficult stages in search of the full moon and face the one responsible for its disappearance.