Filter-goshi no Kanojo

Narumi Hakobe is a high school student who constantly has a blank expression on his face. Even in class, he's quiet and unassuming. His joy in life is keeping up with posts from "Efa," a girl who takes lewd photos and posts them on social media. But soon, he finds out that Efa's true identity is none other than...his diligent and popular classmate Mitsuha Koto...?!

(Source: Yen Press)