The girl's search for the Sagittarius Color Pen leads them to an auction on Planet Zenny, which they manage to attend thanks to an invitation by space idol Mao. When the pen is put up as an auction item, Madoka uses donuts brought in by Pruns as currency to win the audition. However, the pen gets stolen by Mao, whose true identity is revealed to be that of the space phantom thief Blue Cat. When Eyeone appears with another Notrigger, Blue Cat decides to give the pen to Madoka so the Cures can defeat it and revive the Sagittarius Star Princess.

Learning that a mafia boss named Don Octo possesses a Rainbownian ring, Yuni once again takes on the guise of Blue Cat to try and steal it, much to others' chagrin. Sneaking into Don Octo's hideout and retrieving the ring, Yuni finds herself up against a newly appointed space police officer named Ann, only for both of them to be caught by Don Octo. Just as the girls rescue them the duo, Tenjou appears and turns Don Octo into a Notray. With the support of both Ann and the Cures, Yuni manages to defeat the Notray and uses her honesty to convince Don Octo to give her the ring.