Anata no Imouto

"Be my ideal girl... It's been two months since childhood friends, Yuuka and Kouta, started dating. However, due to their inexperience, their "first time" together doesnt go as planned. Enter Koutas younger sister, determined to ensure the couples happiness... No matter the cost... A boy, a girl, and his younger sister... All caught in a love triangle so sensual and immoral, youll want to look away... Yet you wont be able to...