if you're using the walkthrough mod, it's missing the natsuko storyline guide in its objectives section. It tried to streamline side stories such as Logan, Natsuko, etc. into one "main story" section. So from what I recall, you need to sleep in basement manually instead of the sleep button on the top to trigger her story scene where MC sees her in the kitchen at night. I think after that, there's one or two more objectives for natsuko that then allows tanya's office to appear on the map. Not a 100% on that but good luck lol