Aya Drevis is from an old series by Jacksepticeye when he did his Mad Father Videos. She counts as a character though because she was in a video. She is the main protagonist and playable character of the game. She is the only child of Monika and Alfred Drevis, and lives in the large mansion that makes up the setting for the majority of the game.
Aya is a young child who appears to be 10 years of age. Her most notable trait, is her love for her father. She has black colored hair that just passes over her back. Her normal outfit consists of an dark blue dress with a white apron worn over it, and her hair tied in a pink bow in the back. As accessories she wears a golden pendant.
During flashbacks, Aya is shown wearing a simple blue dress with a white dress shirt beneath it. At this age, her hair is a bit shorter than it is, and only reaches to her shoulder blades. It is also styled differently, being kept in twintails by two white bows.
When Aya is turned into a doll in the bad ending, her bangs aren't evenly cut anymore and she is seen wearing a large white bow in her hair, wearing her usual gold pendant with a choker (a type of necklace) and a floor length red ruffled dress with a small pink bow on the left side of the chest. She has a sad, empty expression on her face and her usual dark blue eyes are grey
In the true ending, she is seen as a grown woman. Her hair cut just above her shoulders and Aya no longer wears the bow. She wears an outfit somewhat similar to the one she wore during most of the game.
- In the Laboratory, there are multiple clones of Snowball; one has a cut in its leg and another has its belly torn. It can be assumed that her father had created many Snowball clones to keep Aya content and happy when she may have unintentionally harmed Snowball. This makes Aya sick and she begins having suspicions.
- Strangely, Aya is completely unaffected by screams and pleas for help. In the beginning of the game, Aya heard a terrifying plea for help from her father's basement and ignored it completely. This shows how Aya's considerate to her father's wishes to the point of not caring what goes on in his laboratory, or it shows her lack of sympathy for others except for loved ones due to lack of friends and social events outside her home.
- The bookshelves in Aya's room contain books that are dark in nature for a young girl to read. The Dark Quartet features morbid themes about death and torture, and Horus the Trader and the Red-Eyed Stranger allude to the 'salesman' named Ogre.
- Aya is completely unaffected by the rooms of the trials of murder, in fact, her attitude is almost understanding. For example, after getting attacked on a couple of cases, she simply leaves/runs out of the room and says nothing afterwards.
- In the 'true ending', Aya encounters a red book before leaving, a red book that her father had. The book had 'gross pictures', so Aya refused to read it as a kid. There is a rumor that the book may have consisted of directions to make people into dolls or as a few people have said, the title is 'The New Text of Anatomy'.
- In 'Misao', Aya's clone (Which was shown in the extra cutscene of Mad Father) was rumored to be the same Ms. Library due to some theories Ms. Library said. When you walk into The Library (in Misao) the music from Mad Father starts to play.