Aya appears in episode 3 of the anime. She is a young human who is thrown into prison for a crime she didn't commit. Being human, she is weak and is a target for the Gorilla guard, but is helped by Shin, who is her love interest. The second time she is punished, Morte stopped the attack and threw the Guard with amazing strength, thus saving Aya from being hit.
Later that night, Shin prepares an escape tunnel for her, knowing if he gets caught, he will be severly punished for it. She navigates through it, but comes out of the tunnel in an intense moment with the World Destruction commitee. The Chief of Prison, Victor, grabs her, preparing to throw her back into her cell, when Morte throws Taupe to stop him. Shin grabs Aya's hand, and is seen escaping with the three members.
Afterwards, she thanks the three and walks into the sunrise with Shin's hand in hers.
She is also seen in episode 13, helping Shin move items in the new town while he is bossed by Lia.
She does not appear in the manga nor the video game.
Aya has green eyes with black hair. Being a prisoner, she wears the standard grey long-sleeved shirt and long pants. In episode 13, her outfit changes to a maroon long-sleeved shirt with a high collar and yellow trimmings. Her long pants are also maroon.