Ayaha is Tsubasa's older sister, a renowned and talented former idol. Her success as a singer and an actress made Tsubasa want to become an idol just like her. She disappeared five years before the start of the game as one of the victims of the Mass Disappearance along with Yashiro Tsurugi and his father, with only Tsubasa being left unscathed.
In the present, she reappears after Kiria's concert among enemy Mirages under the control of Aversa. In order to cow Ayaha into obeying her, she feeds Ayaha's negative emotions about the pressures of the idol industry and fear of failing. Ayaha disappears into Illusory 106, and Tsubasa, Itsuki, and Touma give chase, where they eventually find her on the roof.
Tsubasa sings to Ayaha, and her song manages to break through Aversa's control, giving Ayaha the chance to finally reject Aversa and force her out. With Ayaha freed, Tsubasa and her friends pursue Aversa to the concert venue, where they defeat her.
After the battle, Ayaha reunites with her sister, commenting on how much she's grown. After being freed from Aversa's control, she's brought home to her family and takes a job as a secretary at Fortuna Entertainment to provide assistance to Itsuki and the others, with Maiko wanting her to eventually make a comeback as a singer. Ayaha at one point comments that she'd like to do a duet with her sister.
In Chapter 4, the Excellus-possessed Kuen Tarachino threatens Tsubasa with a Mirage holding Ayaha hostage. However, it turns out to be a ruse, as the "Ayaha" in this case is a Mirage in disguise. The real Ayaha is safe and sound.
For most of the game, Ayaha can be found at the secretary's desk at Fortuna Entertainment. She presents a series of sidequests to Itsuki dealing with other entertainers who have had their Performa drained.
The ha of Ayaha is the Japanese word for "Feathers", a reference to the Pegasus Knight class, it also relates to Tsubasa's name which means "wings"
- The designs of Ayaha's jacket when under the control of Aversa resembles the design of the Tactician coat in Awakening.