Ore ga Suki nano wa Imouto dakedo Imouto ja Nai

Also known as: 俺が好きなのは妹だけど妹じゃない, The One I like Is My Sister but Not My Sister, The One I Love is My Little Sister But She's Not a Little Sister

by Seiji Ebisu, Kou Narita

Suzuka Nagami is a beautiful third-year middle school student who has excellent grades and is the student council president. She wrote a novel about a little sister who dotes on her older brother, and the novel wins a light novel award. After they discuss the matter, Yuu is the one who debuts as a proxy light novel author instead of Suzuka, under the pen name Chikai Towano. (Source: Anime News Network)