JK Haru is a Sex Worker in Another World volume 4 - Ko Hiratori and J-ta Yamada

 Back to perhaps one of the most special isekai setting manga's around.

JK Haru, a girl killed in an accident and who is reincarnated in a male-centric world, only getting by as a worker in a brothel.

But while she has plans to advance in the world, her life isn't easy.  A regular group of soldiers becomes more brutal with every visit due to the centurion's influence.  One day, she starts to get into trouble with them, as the mysterious Rain Man arrives, making them take their leave.

She wants to learn more about the Rain Man, even suspecting he is someone summoned from another world as well.  As they talk, she learns this isn't so, but he did meet several of them.  He realises as she asks him upstairs the shop is actually a brothel, and she finally gets to sleep with him as she craves for him so hard.

Later on, Chiba, her former classmate, tells her he discovered he is level capped for his cheats, putting him into a depression as he would now actually need to work to level up.  This has ruined his plan to become the most famous fighter in the arena.  This also leads to his girlfriend Kyori seeking out Haru's advice.  When he is in the brothel later that evening, Haru confronts him.  She takes him up to her room, but after calling him a denigrating name she used for him in high school, he explodes, telling her all about how he feels even before they where brought here, but is rejected by her.

Her co-worker Shequraso is summoned to the barracks in the meantime, Haru and Lupe hearing how she thinks her boyfriend will propose there.  But after two days, she still hasn't returned...

This really is a good isekai series, with a very taking along story.  I can`t wait for the next volume personally.