, but here's some really nice manga I've found that are fap-worthy.
Mysterious Girlfriend X, "Nazo no Kanojo X"
Pic is subber credits. A series about teenage love between a boy and a rather... odd girl. No sex, but so SO sexy, you'll feel like a teenager in love again.
A series of shorts with very few repeating characters, they are all teenagers figuring out sex. It stops short of porn, but the situations are more realistic than what you'll find in doujins so it's very erotic.