no way... never ever is this game gonna end with a harem. Its already ruled out that you can be with more than two LIs at the same time after chapter 8. (and you can only with two LIs at the same time when you choose Maya and Josy... to be precise, you only can follow one route)
The closest thing to a harem would be the throuple with Maya and Josy, and maybe possible other relationships with some "sharing" or so... but not a real harem, its not happening.
Even if you choose the "others" path, which means not going for any of the main girls, i dont think there is anything close to a harem route...
The game is all about choices and the consequences. If you cant decide... than the game is not for you, if you want all the girls at the same time... wrong game too, and no a mod doesnt solve this, it will just screw up the savegame.