Mumyo Tsunataro killed his betrayed fiance Orie and he flees to Utsunomiya. On his way he saves Chisaka Hyobu's daughter Oyu from be attacked by ninja. Thus he stays Chisaka's residence in Yonezawa.

Mumyo Tsunataro killed his betrayed fiance Orie and He flees to Utsunomiya. On his way he happens to saves Chisaka Hyobu's daughter Oyu (She is exactly like Orie) be attacked by ninja. Thus he stays Chisaka's residence in Yonezawa. Chisaka was just trying to stop Forty-seven ronin's revenge against Kira Kozukenosuke by female ninja's sexual entrapment. Chisaka asks Tsunataro to lead female ninja. Tsunataro accepts the request on condition of marriage to Oyu.