On Kyouya Sata's 17th birthday, his girlfriend Erika Shinohara seems to have forgotten the special occasion, causing a mix-up. Erika orchestrates a surprise at Kyouya's place with her friend Ayumi Sanda's unwitting help. However, a mishap outside Kyouya's home sends Erika into a panic, leaving Kyouya to figure out how to soothe his quirky partner.