Considering I have no real programming experience- I can't imagine that this is an easy mechanic to implement. One misstep and the whole thing could become convoluted and ruined. It is fortunate that we have someone competent at the helm.
Basically speaking it's easy to do. It can be summarized like this :
Code:
If storyLevel < 2:
"Oop's, you can't do this, you need to continue the story first."
and
Code:
If girlsCorruption < 2:
"Oop's, you can't continue the story, the girl is not ready."
The way the other game done it is very similar to this, especially since you can't corrupt all the girls in the same time. So, either you have finished with a girl, then you can continue with the story, or you have finished with the story, then you can continue with a particular girl.
But here we are at a totally other level. There's the rank in the family, the stats, the girls' stories and the main story. And everything is linked. The progression of the main story will need that you progress in the family ranking, which itself will need that you progress on the main story.
In the middle of this, there's the girls, with who you'll not being able to progress unless you've reached some rank in the family and some point in the main story ; and perhaps also some point in another girl story. While in the same time your progress with the girls will determine if you can progress in the story and/or be higher ranked. By example, it seem obvious that at one point MC will have to resolve the problem between Luna and Cordia, what will probably mean some "good boy" points with Cordia, and the MC will need them at one point if he want to be higher ranked.
And
@HopesGaming have to juggle with all this to make a coherent game where Luna don't come to the MC saying, "hey, you're a capo now, congratulation. Come here, I'll hug you", while you're still a newbie and she's still so uncomfortable with hugs. There's too many games around there where this kind of weird things happen. So, now it's our duty, while we enjoy the game, to help him track the few cases that he can have missed, and help him handle this in the best possible way. Therefore, never hesitate if something you see seem weird, don't wait for someone else to say it. We each play in our own way, so you can be the only one to reach this special case.
Listen to your leader, elect me as president, I'm the... Oops sorry, wrong speech