This isn’t a narrative of heroes. Since time immemorial, warriors known as musha have dominated the battlefield, granted supernatural energy by their enchanted fits of armor – tsurugi. Minato Kageaki is one such musha, pushed by responsibility to don his crimson armor and problem the best evils of an age. However although madmen and tyrants fall to his blade, by no means will he declare that his battle is correct. 
For the tsurugi he wields is cursed Muramasa, which 5 centuries in the past introduced smash to the land, and harmless blood is the worth it calls for in change for its horrible may. “The place there are demons, I slay them. The place there are saints, I slay them.” These phrases are an oath, the unbreakable Legislation binding him to his armor. However in addition they inform the story of his previous, and of the long run to return.