itch.io

If you go to the paint room on the right hand cupboard, or around there you will be prompted to open a padlock - the code is 951 (can see it in the back of a painting in the room) and you will get dentist tool - then go to cylinder and use the dentist tool to get the key to open lia's door in the morning 

Edit: Just to warn you for the morning, if you go to lia after opening the door and do the erotic option to fuck, your passion afterwards will be reset to 0 - one of the bugs in the game

After the fix, still unsure about the whole paint thing - not sure if there is something to do with the paint in order to progress the relationship with Lia. Also, is there going to be incest in this game? Like the mother moves in to an apartment or can visit family home and do things?