Hayato Izumi runs for student council president at his new high school, but loses to Ui Wakana, a perky and charismatic girl who pledges to liberate love on campus, and throws condoms into the audience during her election speech. He ends up becoming the vice-president on the student council. He soon learns that due to an arrangement by their parents, Ui is going to be his fiancĂ©e, and they have to live together. He tries to keep their cohabitation a secret from the school…