Yui

A young and cheerful girl with long black hair who looks no older than 10 years old. [Kirito](https://anilist.co/character/36765) and [Asuna](https://anilist.co/character/36828) found her in a forest on the 22nd floor of Aincrad. Her true identity is actually a players' self-regulation program for mental maintenance, Mental Health Counseling Program or MHCP. After being forbidden by the game master [Akihiko Kayaba](https://anilist.co/character/36829) to come close to the players at the beginning of the death game, she was flooded with errors and broke down. In the process she became an AI that