Aya appears on the 9th episode of Amaenaideyo. Ikkou and Chitose are called by studio producers after they hear weird voices in a CD recording; when Ikkou and Chitose get to the studio and start praying, she comes out.
She is still wandering this world because she died in a car accident when she was going to the studio for her first day of recording, so she borrows Chitose's body to sing through her.
It is later revealed that she didn't die in the car accident; she took her life because her boyfriend was left in a coma and the doctors told her she wouldn't recover. After her boyfriend awakens from the coma, she then feels relieved and is able to leave the world of the living.
