Six Gravity (Gravi) and Procellarum (Procella), two idol units currently experiencing a dramatic rise in fame. On the day of Gravi and Procella’s handshake event, each of the members are waiting for the start of the event, doing as they individually please. During that time, Shiwasu Kakeru, Kisaragi Koi, and Minaduki Rui meet Syunpei, a primary school student. Syunpei is taking the place of his sister, a fan of Kakeru’s, who had unfortunately come down with a cold. Although Syunpei does not know anything about these idols……