Unlike most mansions, it has relatively few windows for a building its size, which is a beneficial feature, considering the nature of Remilia and Flandre, its main tenants, who both happen to be vampires. In addition, the mansion also houses a large staff working under the Scarlet name.
The most powerful staff members are Hong Meiling, who guards the gates and leads the outer guard, Patchouli Knowledge, who acts as the librarian and private tutor, and Sakuya Izayoi, Remilia's head maid and personal attendant who is the maids' leader.
The mansion's inside is, interestingly, much larger than it is apparent from the outside. This is due to Sakuya's ability to control time and space.
The Scarlet Devil Mansion was the location of the majority of Embodiment of Scarlet Devil, as Stage 4 took place in the library, Stage 5 and the Extra Stage took place in the hallways, and the Final Stage took place on the rooftop balcony.