... it is a about a female mangaka or writer and her new assistant. the story, if i am not mistaken, was that when she was exhausted because of work the young guy had to assist her and it developed into a kind of romantic way.

i saw it some time ago but i couldn´t have it. it was one chapter only.
thanks for your help

Kono Oneesan wa Fiction desu!?

Probably. But it's not hentai so maybe not.

No, he's searching for a hentai, but there are at least 3-4 with the same story like this. I can't remember the names though.

thank you.
i know that it is a bit hard to find it or remember it because i saw it a few years ago.