Erika Shinohara is a freshman in high school who has never been in a romantic relationship, but lies about her imaginary boyfriend to her more experienced friends for appearance's sake, a la “the boy who cried wolf”. When her friends become suspicious of her tall tales, Erika shows them a shot of a good-looking guy she secretly photographed in town insists that he is her boyfriend to get out of the jam. But it turns out that he is Kyoya Sata, the hottest boy in their school. When Erika explains her predicament to Kyoya, he kindly agrees to pretend to be her boyfriend, impressing her with his charming prince-like demeanor. It turns out, however, that he is actually a black-hearted prince with sadistic tendencies and she must obey him unconditionally in exchange of his cooperation.When Erika realizes that she has growing feelings for the “Black Prince”, their relationship that started off from a lie turns into true love!