IIRC you need to be sure to watch the couples in the street at night and that helps level up desires, especially with flashing.Jesus, I normally don't ask this, but is there a way to just set Desire Locks and Vulgarity to max? Played the entire game to the point where you go to Mount Goryo to finish the story off, done as many lewd events as I could, and I've only got a couple desires maxed and most still at level 1. Flashing especially.
Trying to do practically any events to increase things only to be told you don't meet the requirements is really wearing down the game. I just wanna see the H-Scenes and for once doing it "legit" just seems fucking time consuming