Maiko reveals to Itsuki that Tsubasa is going to be holding her first solo concert, and that she has arranged for renowned songwriter Chouten Sawafuji to write her a new song. When he arrives, however, he rejects the offer despite previously being optimistic about it, mentioning that he is already writing a song for someone named "Azusa". Tsubasa explains to Itsuki that the person he was talking about, Azusa Maekawa, was a legendary idol who supposedly died from an unknown illness. Maiko then reveals the truth about her death: her Performa was completely consumed by a hostile Mirage, one that not even Kiria could defeat. Realizing that this Mirage was influencing Chouten, Itsuki and Tsubasa go off to save him.
Arriving at Illusory Daitou TV, the party confronts Chouten and the Mirage controlling him, Pheros, who seems to think she is Azusa. She sings at the party, leaving them unable to act. Fortunately, with encouragement from Itsuki and Caeda, Tsubasa is able to sing Feel, freeing Chouten and countering Pheros's singing, allowing the party to finally defeat her. Tsubasa thanks Itsuki and Caeda for their help, and admits that singing in the moment reminded her why she enjoys singing, causing her Performa to awaken. As the party leaves, Chouten, who has decided to write Tsubasa's song, realizes it's time to move on, and asks Azusa to watch over Tsubasa. After performing Radiant Unity, Caeda thanks Tsubasa for teaching her the wonders of singing, before teasing her about her feelings for Itsuki. Tsubasa's solo concert, with her new song Fly: You're My Wind, is a success, and Chouten offers to write her next song as well. Itsuki promises to continue supporting Tsubasa in her path to becoming an idol.