Desumi invites immobility to a high school school festival. At the school festival, an object called "The Moon of the Black Emperor" is exhibited, and there is a legend that the couple sitting there will be the strongest couple united by eternal love. Two people who swear to sit down absolutely. However, on the day of the school festival, troubles continued and it was difficult to meet Death Beauty and Fudo ... Can they really be the strongest couple? !!