When he was young, modern middle school student Jun Tendo lost his father to a heroic effort to save a child's life. Jun never quite understood that or his mother's comments that a time might come when he'd have to be courageous, too, but when a strange creature pursues him into an old temple he finds himself hijacked back to the Heian Era, where the monk who took him refers to him as the “Savior” who will help the nobles of the time defeat dreadful oni.