Read Vanishing Twin hentai manga on hentaidexy.
summary for Vanishing Twin :
Yeon Janghwa is a more or less average college student: she attends a pretty good university, is pretty good-looking, and has a nice boyfriend. Her a twin sister, Hong-ryeon, on the other hand, is the opposite. Being the good sister she is, Janghwa sets out to help her twin sister…but at what price? The truth is in the details.