I read that doujin about a year ago, the title was like “Lone” Or “Lonely” In it. It was a high school doujin where a boy admires his senpai who is very beautiful and has big boobs, short hair but one day he forgot his notebook in class and when he reached his class, his senpai was masturbating. When his senpai noticed him, she invited him for sex. They started doing it regularly but one day she asked him to have raw sex. The art is very sexy and i want to read it again.