Full Metal Daemon Muramasa – a graphic novel in Japanese anime style. The plot revolves around Tsurugi, a legendary artifact in the form of a set of armor, inside which a living soul is chained. This is the most powerful weapon in the world, capable of subjugating the entire planet. A person who possesses such armor gains the ability to fly and becomes the greatest warrior in the world. Their blades easily tear steel, and the armor withstands any attack.

The action takes place on the island state of Yamato. In this country, a rumor has spread about a mysterious warrior named Musya, dressed in silver armor. He destroys peaceful cities and leaves nothing but destroyed houses and killed citizens. The main character confronts numerous opponents and tries to stop the mysterious and powerful warrior from destroying peaceful cities and villages.

The gameplay is focused on dialogues between characters and numerous interactive scenes. The user's choices and decisions will affect the further fate of the plot, the appearance of secondary events and unlocked narrative paths. The gamer takes control of Minato Kageaki. He carries out orders from the higher-ups and fights deadly enemies.