After placing Buredoran in a cell for indirectly helping the Goseigers get a new power, Makuin ensures Kinggon that he has a plan to remedy this turn of events. At the Amachi Astronomical Institute, having recurring dreams of a woman calling out for her, Moune is overconfident about having the Miracle Gosei Headders. Taking her leave as the others wish to uncover more about Buredoran, Moune hears the voice from her dream and finds the woman to be her mother who has her promise not to tell anyone about her, not even Agri. But when Datas contacts, Moune is forced to leave her as she joins the Goseigers as the others assume their Super forms to fight Makuin with Gosei Knight aiding them. By the time Gosei Yellow arrives, Makuin takes his leave. As Moune returns to her mother, who would like to take her back to Gosei World. Given time to decide, Moune asks Eri for advice before Agri confronts her about her sudden behavior, driving her off. The next day, Moune meets with her mother and accepts the offer as Makuin resumes his attack. Realizing Moune's being targeted, yet conflicted, Agri tells the others that she would. But as Moune realizes her "mother" is an impostor, Gosei Knight exposes the fake as Sarawareteil of the Y?sei. Becoming Gosei Yellow, she and Gosei Knight battle Sarawareteil as the others deal with Makuin before he takes his leave after a Bibi Soldier tells him his scheme has failed. Once the others arrive, the Super Goseigers and Gosei Knight defeat Sarawareteil before forming Ground Gosei Great to destroy her. Later that night, Moune and Agri make up as the latter recognizes his little sister to have matured a bit.