Ero Manga Sensei (Kari) E Sensei to Akazu no Ma (Dengeki Bunko) [Light Novel]

[Machine Translation] I, Izumi Masamune, a high school student and novelist, have a younger sister who is a recluse. Her name is Saori Izumi. She became my sister a year ago, but she never comes out of her room. Today, she is pounding on the floor and making me prepare meals for her. This relationship is not "sibling" at all. I want her to come out of her room voluntarily. We are a family, just the two of us. My partner and illustrator, "Eromanga-sensei," is a reliable guy who draws very erotic pictures. I've never met him, and he's probably a creep, but I'm always grateful! But then, a shocking fact hit me. Eromanga-sensei" is my younger sister! A new series by the "Ore no Imouto" duo!

高校生兼ラノベ作家の俺・和泉マサムネには、引きこもりの妹がいる。和泉紗霧。一年前に妹になったあいつは、まったく部屋から出てこない。今日も床をドンドンして、俺に食事を用意させやがる。こんな関係『兄妹』じゃないぜ。なんとか自発的に部屋から出てきてもらいたい。俺たちは二人きりの『家族』なんだから―。俺の相棒・担当イラストレーターの『エロマンガ先生』は、すっげーえろい絵を描く頼りになるヤツだ。会ったことないし、たぶんキモオタだろうけど、いつも感謝してる!...のだが、衝撃の事実が俺を襲う。『エロマンガ先生』は、俺の妹だった!?『俺の妹』コンビで贈る、新シリーズ!