Yui Rio is a canon character who attends Akademi High School.
Yui has red hair that is styled in a short sidetail to her right. Her eyes are red as well. Her uniform is dependent on the player's choice. She wears a red friendship bracelet on her right wrist, along with red stockings and panties. She has the smallest bust size in the game, set at 0.5.
Yui has the Evil persona. If Ayano tries to take a picture of her without being in the Photography Club, she will glare at her and hide her face. If she witnesses murder, she will compliment Ayano on it and then run away to avoid becoming her accomplice. After that, she will not communicate with Ayano again.
- Yui is currently the only student implemented in Yandere Simulator who has the Evil persona.
- Yui's original hairstyle was replaced in the February 8th, 2016 Build because YandereDev thought that it was "low budget" and "amateur-ish".
- Before being in the Cooking Club, Yui was in the Martial Arts Club.
- Yui's name was at one point Yui Hirasawa, then later on Yui Hirasa. These names were inspired by K-ON.
- Yui's male counterpart is Haruto Yuto.
- Her current name is a reference to the most popular female Japanese names in 2012, first being Yui, second being Rio.
- She used to arrive second to school on the right side at 7:05 AM.