the "region-locked" you spoke of is the censorship DLsite forced to pull to gatekeep foreigner because CC company being fucktard, so now DLsite have to make any and all underage female humanoid looking character disappear from the store that is browser by non-jp user (oddly enough, this doesn't apply to Shota)
this game doesn't have loli, but the girl wearing schoolgirl uniform, and yes you guess it, DLsite decided to flag it because dumbass western is too trigger happy for any underage character, including girl in uniform