nobody plays the game like this though so it doesn't make sense to pretend like the story is good if you start the game from the beginning everytime you finish a 1-2 hour route with one of the main girls. the game is factually a harem game where you get to have sex with every girl in one playthrough and the writing should accommodate for that. nobody does a eve run, then starts a new game to make a grace run, a roxxy run, a run for all the tertiary characters etc
Well, now we've arrived at the problem that arose because DC and his patrons didn't really agree. For the first 1,5 years DC's position literally was that there'd be no harem and that SS wasn't a harem game. Due to popular demand that changed, but then again, it didn't reeaally change and now they are slowly walking that "fuck everybody in one playthrough" thing back.
So what's likely going to happen? You'll probably be able to make clean runs for the main girls and everything else will be soso and that's the best we can hope for and it's pretty intended to be that way. They stopped aiming for real consistency back when they made the decision to enable the harem. At least that's how I see it.
@
MurkyTurtle:
That's why Grace is a secondary character and the mafia girls are tertiary. They weren't and aren't supposed to get anything. As to why they are there? I already mentioned, that Sploosh said, they wanted some more female characters associated with the mafia - after all, this is a porn game, made for male players - and this whole trafficing/drug topic certainly added to the darkish mood. Do they really need more reasons beyond that?
Edit: It's also true that they wanted to raffle a few girls to high paying patrons, which is probably another reason why there are 3.