Reimu, of course, lives in the shrine, which I'm not entirely sure where it is exactly, but it is little a bit out of the way. Somehow it is not really that different from canon other than being located in a City made of towers instead of somewhere in the mountains (because no one ever said I couldn't) and it's about as modest and slightly worn down as in canon too. Basic modest, Japanese style rooms, including a guest room that's mostly used by Marisa when she crashes there, and a supply room where she keeps everything, including a supply alcohol because there probably aren't drinking laws in Union and Reimu wouldn't care if there were (she prefers tea most of the time).

She lives alone, accept for Genji, the old Carracosta shifter priest who comes by sometimes to check up on her, Ruukoto and, again, occasionally Marisa when she decides to crash there after running away from home yet again.