The ultimate life form of Gensokyo (touhou harem x oc) (Completed)

this will be my first touhou story. The story is about our protagonist enters the land of Gensokyo through a mysterious portal created by a busty blonde yokai. And he ended up appearing in front of a shrine and meets a shrine maiden named Reimu Hakurei. And soon became a resident of Gensokyo. But he has no home. So what would happen if he lives in the Scarlet devil mansion? read and find out. There could be some lemons along the line.