Yui is a youthful and pretty woman, wearing a business outfit, glasses, and long light brown hair tie in a braid.
As Nekohime, has a younger teen appearance, darker brown hair, has cat ears and tail, and wear a pretty pink princess dress with ribbon.
In school, Yui is a hard-working and strict teacher that cares deeply for her students. Yui scolds them whenever they are doing something that is against the school rules or when they are acting out. Despite that, Yui wants nothing, but to help them and feel better in school. In the game however, Yui acts more childish, cheerful to the point that some would mistake her for a teenager. Yui is known to be wise and understanding at young people, knowing how to handle them and treat their problem in a positive way.
Not much is known about Yui's past, but at some point she logged into an online game, L.A., and created a female character named Nekohime, becoming extremely popular among many players, including her guild. When Hideki Nishimura asked her hand in marriage within the game, she decided to tell everyone she's a male player to avoid an awkward situation. This broke Hideki's heart, prompting his distrust towards female players. Eventually, she stopped playing the game for a couple of years.
In the game, Yui is a female and on level 98. Her occupation is a Cardinal and her max HP is 22400.