Before playing the game, I'd like to know if the MC is the only one who has sex with the women, or if there will be other men involved or content like NTR/NTS.
Hi! Yes, the MC is the only one who has sex with the women in the game.
However, just a heads-up: there is a plot point where one of the girls cheats on her boyfriend with the MC. So, while there is no NTR involving the MC being cheated on, there is "cheating" content where the MC is the "other man."