The complex dynamic between the Develuke inhabitants, specifically the female royal members, and Earth's weary Rito Yuki, remains turbulent. Princesses Nana and Momo enroll at an Earth School, closely monitored by their sister LaLa, but Momo's yearning for romantic relationships with Rito and LaLa amps up the tension. Things spiral out of control when Yami, the Golden Darkness, appears with a group of high schoolers under an ambiguous power. Rito's fate might solely depend on the assistance of a particular semi-demonic princess.