Aya is a girl around Mana's age and height with fair skin, straight black hair styled in pigtails. She wears a pair of glasses with pink rims over her eyes, which have brown irises. Her school uniform consists of a white long sleeve collared shirt, with a medium length teal skirt and matching tie, black socks and brown tipped shoes. During the colder seasons, she wears a light teal, long-sleeved jacket over her collared shirt. Her casual attire usually consists of a plain, cyan loose blouse, with dull blue striped skirt and brown belt.
Before class, she and Mana read an article that another woman fell into a coma recently. Aya describes that they become shrivel like old women before falling into coma. Hearing a thump, they see Tsutomu lumbering through the halls. After he passes them she asks if he's alright and expresses that he appears to have not slept in days.
- She originally had brown hair when she first appeared and in Episode 38, but was changed black in subsequent episodes.