Alright, I put in a bit of effort and with the help of a few image translations managed to work out the puzzles:
Code to the kitchen cabinet is 0304. The knife inside is used to unlock other doors.
Check under the pink mattress in the room to the right of the kitchen to find a puzzle box. The combination is Club, Club, Spade, Heart, Diamond. Or left, left, right, up, down. Inside is the oil you'll need for anal scenes.
In the same bedroom is a cupboard with a locked container inside. The combination is 4649427. Inside is a picture frame that you use as a shield to prevent getting stabbed by the girl in the kitchen.
In the parents' bedroom is a cupboard with a safe inside. The combination is 0329, their anniversary date. Inside are shackles you can use on the girl who is sleeping in the living room at 14:30.
Speaking of which; yes, there is a living room. You can get there by clicking on an arrow to the right while in the kitchen.
There is an elusive fourth girl who can be found by returning to the 20:30 timeslot. After retrieving the knife and using it to enter the locked room, open the cupboard instead of clicking on the girl. Inside the cupboard is another girl, but don't click on her either. Instead, click to either side of the screen to turn around and prevent an attack from behind.
That's probably enough to get everyone to all the scenes. As dark as it is, there are some pretty nice animations to be found so a little sleuthing was worth it.
Edit: Haven't worked out how to unlock the epilogue yet. The final unchecked box in the Notes section doesn't translate in a way that gives any kind of clue.