Oh, forgot to mention that when you click to view their affection/love stats, it will also give you hints if you haven't gotten her first 3 scenes from the top. Mostly revolves around giving them a specific item gift item they want (The grey haired cap girl wants you to craft a special sword at some point I think) and then talking to them immediately after, or to click on your desk in your room and pick the first option and pray that the girl you're trying to H shows up to talk to you. Also, once you've unlocked all their scenes you have an option to give them a special item know as a contract, which I assuming is just a marriage proposal. It seems like you can only give it once so pick your waifu carefully as it'll unlock a forth sex option request when you talk to them. I messed up and now I have to go way back to give the item to someone else so RIP.
I also found a strange bug where for some reason the blue haired loli kept showing up to visit me when I picked the option to stay in my room, I had to reload a save to stop the bug, it never happened again after she visits me so I have no idea what triggered it.