The story centers around Erika Shinohara, a vain 16-year-old girl who tells her friends about her romantic exploits, but she actually has no boyfriend. She claims that a handsome boy in a candid photo is her boyfriend, but it turns out that boy is a schoolmate named Kyouya Sata. She has no choice but to make him her fake boyfriend. Unfortunately, Sata may look like a sweet person, but he is actually an ultra-black-hearted sadist. Sata takes advantage of Erika’s weakness and treats her like his dog.
Fifteen-year-old country girl Suzume Yosano has to move to Tokyo to live with her uncle due to her father’s transfer. She bumps into a mysterious man who ends up taking her to her uncle’s place after she gets lost. Turns out, Suzume will be seeing him a lot more often once she starts school because… he’s her homeroom teacher?!