The DLC girls are all going to eventually be made available for purchase. Different Supporter tiers get different benefits regarding these DLCs.
T4 and up get Early Access and get to play them as they're being developed
T3 gets free DLCs when they're finished
T2 gets 50% off DLCs when they're finished
We WILL be doing DLC giveaways in the Discord here and there as well, and we may do community freebies as well, so people who are unable to support financially can have chances to enjoy them too.