The Shogun's Vault I: Tomizo, a master storehouse-breaker who has been released from prison in Denmacho after serving five years plans to break into the Edo Castle gold storehouse to avenge the death of his father, who died a violent death at a gold mine on Sado Island. With the help of Hanji, a playboy who took care of him in prison, as his partner, Tomizo decides on the night of fireworks to be held in Edo Castle as the day to carry out his plan. Kanpei, a wise man, is suspicious of the plan.