The Brat I Hadn't Seen in 10 Years Turned into a Pure, Beautiful High School Girl.

Yuu Arizuki returned to his hometown after quitting his job at an exploitative company in Tokyo. Just as he was getting ready to start a new life back home, he met a beautiful and innocent high school girl, who turned out to be Haruyama Miya, one of the little girls (brats) Isamu used to play with when he was young. But Isamu didn't recognize her because of how much she had changed after growing up...?