Ayano Aishi is the protagonist of Yandere Simulator. She is known as "Yandere-chan" to players of the game, and has been given the cute nickname "Yan-chan" by her classmates.

Since early childhood, Ayano has suffered from an inexplicable, incurable condition. In short, this condition leaves her with a perpetual sense of being empty, hollow, and incomplete. As a result, she has never been able to experience satisfaction, fulfillment, or happiness, and has not been able to experience emotions in the same capacity as other people. As she grew older, she learned to pretend to be a normal person in order to avoid drawing negative attention from others, but was never able to feel any degree of empathy towards other human beings.