Devil Mansion Stage 4 boss, and a playable character in Immaterial and Missing Power, Scarlet Weather Rhapsody, and Hisoutensoku. A scholar who is a friend of Remilia Scarlet. She resides in the library of the Scarlet Devil Mansion, and is the de facto librarian. In fact, she rarely leaves it and is somewhat of a hikikomori, choosing not to leave because the sun damages her hair or the books. She has command over the seven elements (which the Japanese days of the week are named after, making her the "One-week Wizard") and is theoretically an extremely powerful magician. Patchouli is the name of a plant, from which oils and perfumes can be made, and the surname Knowledge is a rather literal reference to her studious nature. However, her constitution is very poor and asthma often prevents her from reciting her spells. This is also reflected in the fighting games, where she moves slowly, and likes to keep a distance between herself and her opponent. She has a bitter relationship with Marisa, who tends to 'borrow' her books without asking. She is fairly short. Species: Human Ability: Manipulation of time Residence: Scarlet Devil Mansion Stage 5 boss, and a playable character in Perfect Cherry Blossom, Imperishable Night, Phantasmagoria of Flower View, Double Dealing Character, Immaterial and Missing Power, Scarlet Weather Rhapsody, Hisoutensoku, and Unconnected Marketeers. She is the head maid of the Scarlet Devil Mansion. Sakuya is the only human living in the Scarlet Devil Mansion,『三月精 第2部』「上海アリス通信 三精版 第5号」（『月刊コンプエース』Vol.7 p.275。実質的には「第6号」なのだが誤植で「第5号」になっている。単行本未収録）。 and is responsible for its upkeep. She uses humble speech to her mistress Remilia Scarlet and friend Patchouli Knowledge, but speaks less formally with others. She is tall. The color of her eyes changes with each work, and ZUN has stated that "she plays the role of a human maid about 10-20 years old" and "perhaps she is a character in her early teens", and in Perfect Memento in Strict Sense, according to Hieda no Akyuu, "she claims to be in her late teens." Sakuya has the ability to manipulate time. Furthermore, it also seems she is able to change the speed at which time flows. However, as it is difficult to reverse events that have already occurred, and since she is not able to return broken things to how they were originally even if she reversed time, in actuality, it is not possible for her to reverse time.『香霖堂』単行本第4-5話 However, she