In the Edo period, at the remote village of Okitsu, the evil cult leader Koushirou uses ninjutsu to bewitch sharks and forces them to attack local pearl divers so the cult can steal the pearls from their mangled corpses. Desperate for help, the village chief hires Kotaro Shiozaki, a guard at a nearby temple, but Kotaro soon finds his path blocked by lady ninja Kikuma and a gigantic shark that doesn't seem like something from this world.

Mai is a member of the Salvage Mice, a pair of thieves who return stolen treasures to their original owners. Mai is betrayed by her former partner to a gang of thieves. She sets out on a path to restore the reputation of the Salvage Mice name and bring her partner's new gang to justice.

The descendants of the legendary Fuma ninja clan face off against the Tokugawa shogun's family of Yagyu samurai as they kidnap women in the hopes of finding a concubine for the shogun