Anyways, now you can head back to the town with the guards, and use the Castle Crest, they'll move aside. Save at the teleport point here.
TELEPORT POINT 6
Secretary [Hard] [Weak Point: None]
H-Maid [Hard] [Weak Point: Breast]
Nurse [Hard] [Weak Point: None]
(Boss) Queen Erotica [Easy] [Weak Point: None]
Okay, now that you're inside, talk to EVERYONE OUTSIDE the castle, including everyone in the houses (there's one house kinda hidden away, so look around). Once you've done that, go into the castle and go west, you should see a guard hiding in the forests. Talk to him from behind. After a bit of dialogue, head back into the castle and examine all the houses. You should fine a Castle Key.
BUY TWO MAGIC STARS!!
You can head into the interior of the castle now. There's one path blocked by a guard, and the other path leads to a bunch of treasure, but it's blocked.
When inside, go north, and go west as soon as possible. Go south into the room, and look around. You should find a pair of stairs. Go down, and you'll head into a dungeon like area. Navigate through the area, removing boulders where you see fit. Keep going, and you'll find a pair of stairs going up. This will lead back to the main room, and just follow the path, and you'll find the Queen of Erotica.