Kazuya Shibuya, a young man, unexpectedly receives an invitation to join a game called the Savanna Game through an anonymous email. The game is a sanctioned killing game meant to motivate the repressed youth of modern Japan. Shibuya, along with his comrades Kotegawa and Kudou, engage in peculiar battles that traverse various dimensions and eras, featuring dragons and the Shinsengumi force of the shogunate era.