Looking for this hentai I saw a while back. The artstyle was really good, and basically the trope goes as follows:
A guy is out on vacation to this place that has an onsen, while out he bumps into this girl lying on the road and finds it was this girl in his class before. Apparently the girl used to be really quiet and everyone found her weird.
He pities her and brings her back to the guesthouse he’s staying at, and afterwards when they’re both in yukata he finds that she’s actually really cute and they do the deed.
iinw the girl missed out on a school trip to this very place they’re at rn too, so it was kind of repaying back her missed school trip.
Thank you so much!