Mizu Shobai (Water Business) blends two stories, one of a geisha who is lost at sea and another of the first geisha to circle the world.

Echizen Fukui Domain. Futago Rokubei, who backs down even at the sight of a gecko, is called "Coward Samurai" by others. His sister Kane blames him for not having any marriage proposals. One day, the lord's martial arts instructor, Nito Kouken, kills one of the lord's attendants, Kano, and flees, leading the angry lord to issue an order to kill him. However, there is no one in the domain who can match the swordsmanship of Nito. Rokubei, in order to clear his long-standing dishonor, volunteers to be the one to kill Nito and sets out on the journey, leaving behind Kane who tries to stop him in tears.