So... I think I somehow managed to softlock my game...
I was going for a virgin, non-perverted route. I have received 2-3 perversion due to unavoidable story events, but nothing more than that. I cleared the outpost as soon as I got there, reached Jabreaux, went to the tower up North, did that, went to the village at the Southwest, cleared that as well, beat Unicorn without giving Shera's virginity.
Then I went to the slums and decided to go for the Alcohol Shipment infiltration, so I went to the last city. Since I got the Litograph resonating, I went to the guard in that mansion and spoke to him, but didn't seduce him. I went back and did the whole infiltration in the slums, completed that bit, completed the tournament in Jabreaux, but now I can't proceed.
My "Next" indicator is past the guard in the mansion gate, but I can't get to it without seducing the guard or (I guess) showing up with a vase; however, Shera absolutely refuses to go to the Red Light District. I can't get there through the guard nor through the passageway that she can't hear about because she's "an outsider."
After winning the tournament, she mentioned something about "checking some of the cities she has left" so I think that's where my softlock comes in. I should be able to go to the RLD after getting one treasure, but since I went to the last city before that line of dialogue, the flags are all messed up now. Does anyone know if I'm missing something? I have the shield, armour and sword treasures.
EDIT: It wasn't a softlock, but it might as well had been. There's a box in the Slums hideout that has a secret button that opens a flight of stairs to a room that has a white jar that counts as a vase. How are you supposed to know about any of this? Get tired and frustrated, then just go across every map mashing "Z" on everything like I did...