Harem Members: Aqua, Darkness, Megumin
Ya, that's it. This may be a multiverse fic, but Kazuma will only have these three in the harem, and everyone else won't be included at all, period. No cheating or NTR will happen in the harem.
One more thing to be noted is the fact there won't be any Yuri in the harem. Yes, NO YURI IN THE HAREM!
One more thing to remember. Kazuma, won't be getting into a relationship with anyone till he has done a few world travel quests in the Group Chat system missions. Harem is only an aspect of the story and not the main focus.
Everyone will start as friends and after some time they will develop to become something more, but they won't be anything more till I feel I built enough of a foundation for this harem to work.
Oh ya, he will marry all three of them together at the same time. They all start a relationship together after enough events build up for them to have a logical reason behind it.