有須川 綾華

Ayaka is a third-year student at the same University as the protagonist. She belongs to the Faculty of Pharmacology and is a pharmaceutical genius who is highly admired by the professors.

She is a scary woman with a self-righteous side who makes the protagonist take an experimental drug that reverses a person's gender to aid her in developing an antidote for it. The drug she is tenting is called "XYX".