A Star is Born is the first chapter of Tokyo Mirage Sessions ♯FE.
After the events at Daitama, Touma takes Itsuki and Tsubasa to Fortuna Entertainment, the media company run by Maiko and the career place of Touma and Kiria. There, he takes them to the Bloom Palace, located through the back door of the office and home to Tiki, a Mirage posing as a Uta-loid program. Tiki explains that she doesn't have her memories, as seems to be the case with all Mirages.
Once the party returns to the office, Maiko decides to have Itsuki and Tsubasa begin training for their careers in the industry, though the former doesn't know what he wants to do yet. She sends them to the Uzume Lesson Studio in Shibuya, where they meet Barry Goodman, a former guitarist and their new instructor. However, he gets frustrated with Tsubasa's inability to "sing from her heart" and storms off. After Tsubasa leaves in sadness, Kiria arrives to begin her training, and gives Itsuki tickets to her next concert, believing that it will help Tsubasa.
At the concert, Itsuki, Tsubasa, and Touma watch as Kiria performs Reincarnation. As Kiria predicted, this helps Tsubasa realize that she needs to sing to make others happy. This causes her Performa to evolve due to her personal growth. However, Shibuya is suddenly attacked by enemy Mirages, and Tsubasa is shocked to discover that they are being led by her long-lost sister, Ayaha Oribe. When Ayaha sees Tsubasa, her head begins to hurt and she is forced to retreat into Illusory 106, though not before injuring Kiria after she protected Tsubasa from an attack.
While exploring the Idolasphere in search of Ayaha, the party runs into Yatsufusa Hatanaka, a high-profile figure in the entertainment industry, who somehow wound up in Illusory 106. They eventually find Ayaha, but discover that the Mirage possessing her is preventing her from hearing Tsubasa. Caeda proposes that Tsubasa sing to Ayaha, similar to what they did together in her childhood. After performing a Radiant Unity, the party travels to the rooftop of Illusory 106, where Tsubasa's song successfully reaches Ayaha. The Mirage possessing her, Aversa, threatens to force Ayaha to kill her sister, which causes their bond to weakened and subsequently severed by Itsuki and Chrom, freeing Ayaha and forcing Aversa to retreat to the real world to find a new host. However, the party defeats her, though she warns that others like her will be coming as well.
After Shibuya returns to normal, Kiria is let out of the hospital, and Tsubasa and Ayaha are reunited. Back at Fortuna, Maiko proposes a celebration, and Kiria agrees to join the party, much to Tsubasa's delight. Also, Maiko has hired Ayaha to serve as Fortuna's secretary as a form of rehab before sending her back to the entertainment industry. When asked if he has found a preference to what he wants to do yet, Itsuki confesses that he hasn't, prompting Maiko to have him try everything to see what he likes.