Microsoft is hoping to revolutionize the way that companies use messaging service Line to promote their products, with the help of an artificial intelligence program last seen posing as a high school girl.

Line users were wowed by the appearance late last month of Rinna, a "schoolgirl" operated by Microsoft whose life-like interactions and quirky sense of humor charmed many into forgetting she was just a computer program.

Young men nationwide professed their undying love for the character — whose profile picture shows a girl in school uniform with her back to the camera — as more than 300,000 users became "friends" with her in the first week alone.