One of the better known mangaka in the erotic genre. Uses computer a lot for his color graphics. A lot of weird beings appear in his manga: hermaphrodites... 

Some of his early work was published under the name Masaki Katō. He has been publishing since 1986.

Yui is known for his computer-assisted drawings, manga, and web-images of pretty and sexy girls (bishojo). He specializes in romantic comedies, sometimes supernatural and often sexually explicit, about these girls and their male and female friends.

Three of his works have been translated into English, Misty Girl Extreme, Hot Tails, and Wingding Orgy Writing about Kagome, Kagome, the French manga dictionary Dicomanga pointed to Yui's large usage of computer software which gives a particular yet slightly icy tone to his universe. Also writing about Kagome, Kagome, SplashComics noted that Yui used the technique of using photographs as backgrounds. Derek Guder, writing about Hot Tails, described Yui as "an adult manga king", enjoying his unique "mix of sex, humor, and bizarre imagination. He simply lets his id run wild, and we stories that are as surreal as they are sexual". Guder found the artwork of Hot Tails "still a bit unpolished and busy in these older stories, but his style is undeniable. The art is gorgeous, the ladies are sexy, and the premises too bizarre not to enjoy", giving it a rating of four out of four stars. Yui's Hot Tails has been called the best known exponent of the futanari genre in the West.