Eita Kidou is a high school freshman who unlike his other classmates has no interests in dating and only wants to focus on his schoolwork. Up until recently he has lived a regular school life with his childhood friend, Chiwa Harusaki, who has become like a sister to him. However, once the school's most beautiful girl, Masuzu Natsukawa, blackmails him into being her fake boyfriend his high school life quickly changes. Now he has become the envy of all of his classmates. Things will only become more complicated as a fierce battle over Eita pursues as Chiwa will not let things go without a fight.