Kagura is a samurai girl known as the "Sword Saint" for her mastery of the way of the blade. And Raito is a boy who belongs to the race called "Ninyou" that is hated by the humans. The two met in their childhood and spent happy times together as best friends, until the difference in their races separated them. Kagura took up the sword for Raito. For the sake of them living together. The bond between the two transcends years, walls, races, reality! Surpass it all!!

(Source: Shogakukan, translated)