A samurai mecha that actually commits to the duel as its smallest, truest unit of storytelling. Every fight is a negotiation between two philosophies of the blade, not just metal on metal. Musashi and Kojiro aren't rivals locked in plot necessity; they're asking the same question in different languages, and the show knows the answer matters less than the asking.

In an age of civil war, the land of Zipangu is home to both people and gimmick warriors, a kind of superhuman robot, and both sides fight for power. Musashi, a samurai gimmick warrior, sets out to become the greatest samurai of all. Along the way he fights one battle after another and meets many heroes and villains, among them Kojiro, a skilled swordsman who becomes his lifelong rival. Later their general sends Musashi and Kojiro to escort his granddaughter, the princess. She is spoiled and hard to handle, so the trip turns into one mishap after another, and before long the group is pulled into a struggle for control of the country. The series is an action adventure with mecha elements.