Patchouli Knowledge is Remilia's magician friend. She was probably treated as a guest when she first came to the Scarlet Devil Mansion, but now that so many years have passed... it's harder to define her actual position in the mansion.

Sakuya Izayoi serves Remilia as her head maid. She is also the only human resident of the Scarlet Devil Mansion, but that doesn't mean her combat prowess or ability is in any way inferior. In fact, she boasts a fairly high place in the mansion's pecking order.

Houses built separately from the main residence for the purpose of lodging guests are known as guest houses. They are often equipped with all the amenities, such as toilets and bathrooms, required for the guest or guests to comfortably live there on their own. However, in some parts of the world, a guest house can also refer to a type of cheap hotel-style lodging.

The Scarlet Devil Mansion's guest house in the forest has practically become a storage house because they hardly ever get any guests from afar. Remilia has ordered Sakuya to regularly clean the place on the off chance that it might one day be used for its intended purpose, but it was never a high priority. Remilia assumed Sakuya would just give it a light dusting from time to time. However, when Sakuya went out to clean the guest house this time, things were a little different. Patchouli decided to tag along.

Patchouli accompanied Sakuya because she wanted to search the guest house for her lost magic books. However, she didn't want to be a burden, so she decided to look for her books while helping Sakuya clean. You'd think the cleaning would progress faster with more hands, but that was only at the start. As soon as Patchouli saw her magic books, she expressed her joy by sitting down and talking about each and every one of them, forcing Sakuya to work around her...