The protagonist, Niihara Daiki, has been used as a personal errand boy by his domineering sisters ever since he was little. Whenever Daiki is home, he handles all the chores. The moment he tries to protest, they start hitting him and unilaterally cast him as the bad guy. This is his daily life.

Fed up with this routine, Daiki one day hears about a hypnosis device from an upperclassman at his university. He tries it half in disbelief, but the effect is immediate - his sisters become obedient to his every command.