Fifteen years after Ishida Mitsunari lost in the battle of Sekigahara, Tokugawa Ieyasu foresees his unavoidable battle with Toyotomi Hideyori and goes into Fushimi Castle. At the night, Hattori Hanzo, the leader of 36 Iga members who were performing as guards of the castle, perceives the existence of a ninja and captures the sneaker. Unexpectedly, the ninja turns out to be a woman, and Hanzo rapes her. Years later, when the nation is under the rule of Iemitsu, the third Tokugawa shogunate, a magician pair of a mother and her child appears in a busy area in Edo. The mother is the woman ninja, who is actually a daughter of Mitsunari. The pair of mother and son ninjas is waiting for the opportunity to take revenge. They learn the opportunity has come, hearing that Iemitsu will hold a martial arts tournament on the premises of one of his direct retainer, Mizuno Jurozaemon. The winner will be awarded with 10 swords that were captured from Toyotomi family's ware-house. Wakakage, the son ninja, sneaks into the mansion of Ono Jirouemon, a sword instructor of the shogunate and a judge of the tournament, and copies the written proceeding of the tournament. Then, he goes back to his mother, who orders him to steal the 10 swords!