Minagawa Ichiri is troubled by both positive and negative outcomes, leading him to pursue actions that avoid such situations. Unfortunately, due to his parents' employment, he is consistently uprooted and forced to switch schools. For his latest move, he has enrolled at Reimei Academy, one of the well-known private schools recognized as the "Seven Sisters." During a tour of the campus guided by Kirishima Shitone, the vice president, an unexpected assault takes place. The assailant is targeting individuals with lengthy, black hair and wielding a sword, seeking vengeance on "Double Edge," who employed a power called "Idea" to make her principles come to life utilizing a wrist device called "Codec" to execute one of her closest pals.
