Can someone tell me which manga this is from?

Clearly a “lost top at pool” situation. But I tried using Google lens and even saucenao(which never works but whatever) and didn’t find anything at all. It doesn’t help that it is in japanese and I don’t understand a thing 😅
This was sitting on my downloads from quite some time ago so I don’t remember where I got it, but just one panel like this I probably didn’t know where it was from before either. If some enlightened soul could tell me the name 🙏