In the first term of the new school year, Harumigahara High School, a group of students decides to throw a party to celebrate the end of summer vacation. The students decide to wear yukatas, which are Japanese clothing, and they invite the white prince and the black prince to join them. The girls decide to dress up in kimonos and the boys in yukata, which is a traditional Japanese costume. The white prince, however, does not wish to participate in the party because he does not want to be associated with the "black devil," the girl who he loves the most