Gyakuten Enkou: Ore ga Kawareru Sekai

"Shinji" has been harshly dumped by all the women he's ever dated.
He's taken to drowning his sorrows in alcohol, and one day, he drank until he fell asleep with a porn manga in his hand. When he woke up the next day, his phone was flooded with with messages inviting him to compensated dating.
He agrees to meet up with "Mari," a woman who offered the lowest price among them, and only after doing the deed with her, did he realize that he's been transported into "a world of reversed morals"…
(Source: Melonbooks, translated)
Notes:
- Released at Comitia 144, Comiket 103, Comiket 105, Comiket 107.
- A live-action AV adaptation (MIMK-155) was released on May 31st, 2024