Pretty simple game. No idea what the story is, but you go from Dungeon (Scene for boss and red miniboss) -> Sex scenes at night ->Talk to king ->Get new outfit to use for 1 "special" scene ->Dungeon. all the way until the end.
After everything is done you have free play mode which allows you to revisit all scenes, and the bosses/minibosses are wandering around town so you can walk into them for their scene.
For the scenes at night, you basically talk to all the npcs on the yellow road until 1 gives you a quest, whereby you get teleported to the bat and he shows you the sign of the building to enter. After entering the building you find the new npc to talk to and equip whatever appearance he asks (Some black tights, naked, breasts showing, pussy showing) for and the scene starts.
Attached the save file for those of you who are lazy to finish the game. Almost all buildings have scenes in them. Buildings with an npc at the door are the "special" scenes where you need to change to a specific outfit, and there are 3 npcs in the city itself (Left map, boy at bottom left area, clown at left area. Right map, dwarf guard at the market). When you talk to and npc with a scene, he will tell you what outfit to put on with a speech bubble (the 4 mentioned above). The special outfits like sailor costume, gym/bloomers outfit are only used for 1 special scene each.