This "sibling romantic comedy" revolves around Masamune Izumi, a light novel author in high school. Masamune's little sister is Sagiri, a shut-in girl who hasn't left her room for an entire year. She even forces her brother to make and bring her meals when she stomps the floor. Masamune wants his sister to leave her room, because the two of them are each other's only family. Masamune's novel illustrator, pen name "Eromanga," draws extremely perverted drawings, and is very reliable. Masamune had never met his illustrator, and figured he was just a disgusting, perverted otaku. However, the truth is revealed… that his "Eromanga-sensei" is his own younger sister! To add to the chaos that erupts between the siblings, a beautiful, female, best-selling shoujo manga creator becomes their rival!

Grigio Academy Boarding School. Students who attend this school in two countries and reside in their own dormitories. Inazuka and Persia are rival dormitory leaders, but in secret they love each other. Now, they have to keep their relationship a secret from their dorm mates, or ruined things will happen to them.

Set off by a sweet chance encounter, 16-year-old Su Zaizai finds herself helplessly drawn to Zhang Lurang — her smart, charming yet distant schoolmate.

Ao Horie’s father, a popular erotic fiction author, chose Ao’s name because A stands for “apple” and O stands for “orgy”! Desperate to escape her father’s legacy and get into a prestigious university, Ao devotes herself to studying instead of pursuing romance. She has no time for boys, but there’s just one problem: Kijima, her handsome and popular classmate, just confessed his love to her! And to make matters worse, she can’t stop thinking dirty thoughts about him! Looks like escaping her father’s influence will be harder than she thought…