One day, Rui caught sight of the "Tsukiusa." mascots (a familiar sight at the "Tsukino Dorms") walking. These "Tsukiusa."s were apparently looking for something important, so Rui decided to give them a helping hand.
Actually, these "Tsukiusa."s are also the members of the female idol units "Fluna" and "Seleas", who also belong to the same company. These girls, who originally were from the Moon Society, for some reason became "Tsukiusa."!
To be able to return to their original forms, Rui and the girls, embark on a strange and charming journey!