Kono Manga no Heroine wa Morisaki Amane desu.

Overview

Aizumi Kyousuke's goal is to debut as a mangaka while still in school, however, his childhood friend, Amane, sees this as an impediment for him to concentrate on his studies now that he started college, so when he asks her for help to be the model of the protagonist of his manga, she will seek to do it "wrong" to take that idea out of his head, not knowing that her "strange" poses would end up motivating him even more.

Source: AniList