Basically, if you fuck any of the girls, the relationship turn toxic and the epilog outright says they'd have better off never meeting you. The good ending is if you don't try to fuck anyone, and even then you'll see some heartbreaking (and unsettling) stuff along the way.
Thankfully, the maids seem fair game, at least with my choices. If I couldn't have Yoko, I'd have to give this game a 0/10.