i think you're talking about usotsuki boyfriend!
https://www.mangago.zone/read-manga/usotsuki_boyfriend/
OH MY GOD THANK YOU SM!! YOU FOUND IT SO QUICKLY ( ˘ ³˘)
I read this a lot since my teen days!! Actually i think this manga had a yaoi potential and im pretty sure it was dropped??
What omg I can't believe it was dropped that's so sad I was kind looking forward to see if the guys ended up together (；′⌒`)
Right!? But no i think the story just goes on with different kinds of clients that they deal with
There was this old obscure manga I read a long time ago about three brothers running a detective agency or something for money and one of their first clients was a celebrity that had to deal with a stalker(?) anyway there was this really specific scene where the oldest brother is sitting on the beach with another guy and he offers him soup from a thermos and the other guy mumbles that he wishes the brother was a girl instead… this is really not to go off on but if any of you know that would help me sm! I read it on here so ?(。ヘ°)