hello /h/
I've been searching all over the place for a certain doujinshi (might be a tank) that I saw years ago here back when I didn't save much.

it's set in a school, and the protagonist is either foreign or blonde guy who may or may not be wearing glasses. some girl takes him out by the stairs and blows him and comments on his phimosis.
next day in swimming class she's doing blowjob motions with her mouth and he gets hard in the pool and embarrassed.
boy falls in love, follows her, finds out she's getting fucked by some teacher and tries to intervene and a whole bunch of sex happens.
And the ending page(s?) I think is a time skip to when both the guy and girl are adults.

it's pretty vague but I have faith in /h/.
dumping a huge chunk of my favorite stuff irregardless because /h/, you deserve it.