A giant UFO has appeared over Oedo Castle, and the Mystical Ninja is off to save the world again! Control Goemon and his giant robot, Impact, Ebisimaru, a truly twisted ninja, Yae, the part-time militant mermaid, and Sasuke, a mechanical warrior. This brave band must travel from town to town, collecting information and purchasing helpful items in their quest to defeat the dreaded Peach Mountain Shoguns.