Twin sisters Sayo and Hina temporarily attend Middleton High School to help super-spy Kim Possible stop the evil Dr. Drakken and his serious scheme to take over the world. However, things go different from planned when new boys Eric and Johnny ask Kim and Sayo to the upcoming prom.

After the group known as "Gateway" was formed by Nishikino Kirei, every band and idol group from the music industry saw the immense potential and danger to their ranks due to the power and popularity of Gateway, this is a musical warfare.