If you're looking for manga similar to Eromanga Sensei (Light Novel), you might like these titles.
Yuu Nagami, a high school student aiming to become a light novel author has a little sister named Suzuka. Suzuka is an excellent student with good grades and great looks, but she's very cold toward her older brother. Every year Yuu keeps failing at the preliminary rounds of the light novel contest, but one day Suzuka reveals a shocking truth. The flirty sibling romantic comedy that Suzuka wrote has won the light novel contest! To make matters worse, Suzuka doesn't understand anything about light novels or moe so she begs Yuu to stand in for her under her pen-name, Towano Chikai!
Yuu Nagami, a high school student aiming to become a light novel author has a little sister named Suzuka. Suzuka is an excellent student with good grades and great looks, but she's very cold toward her older brother. Every year Yuu keeps failing at the preliminary rounds of the light novel contest, but one day Suzuka reveals a shocking truth. The flirty sibling romantic comedy that Suzuka wrote has won the light novel contest! To make matters worse, Suzuka doesn't understand anything about light novels or moe so she begs Yuu to stand in for her under her pen-name, Towano Chikai!
Itsuki Hashima is a novelist who's hopelessly enamored with the idea of little sisters and is constantly surrounded by colorful characters. A world class genius and love-guru who's beauty almost seems a waste on her. A girl who's constantly troubled by her friendships, love interests, and can't even find refuge in her dreams. A ridiculously talented illustrator. Each of them have as many problems and worries as the next and they never have a dull day together as they play games, travel, and work together.
Yearning for the world of erotic novels, Shiina Keisuke triumphantly joins the business as an editor. The author he yearns to work with is Kuroki Chihiro, however everyone is afraid of her because she is a devil to work for.
After being separated for six years, twins Akito and Akiko Himenokouji have joyously reunited and are as close as ever - in fact, maybe a little too close for Akito’s comfort, as his sister has developed an unrestrained brother complex! Though her brother doesn’t take her lustful feelings seriously, Akiko is determined to set the record straight with the other ladies around him, including the three other beauties that live in his dorm and want the boy for themselves. Every morning, noon and night, the girl continues her mission to cross the line with Akito, and she won’t let any girl or sense or morality get in her way - for as long as there’s love, it doesn’t matter if he’s her brother!