Yep, so the reason for this is that the branching isn't just a case of picking a route for each girl. Some routes have additional choices within them that can lead to different content. Using Sasha as the example, you can make her submissive and you get content associated with that, but what if you didn't get to punish her after the first ghost hunt? In which case, you get a different scene if you choose to punish her later on. It's that kinda thing. I do this because I like choice in games, but I know not everybody has the time to go through a game multiple times to get everything, so you can unlock all scenes at the end of the game if you really want.