A magician youkai, resident librarian and instructor of the Scarlet Devil Mansion. She has mastery over the seven elements corresponding to Japanese weekday names - Sun, Moon, Fire, Metal, Wood, Water and Earth - earning her the nickname "One-Week Wizard", but her reclusive lifestyle (she's apparently not left her library in 100 years, which is interpreted in some doujins as signs of hikikomori behavior) has taken a toll on her health, limiting her powers by way of asthma and anemia. Due to her baggy clothing, her bust size and overall body shape are still open to debate.
Person: very long hair, purple hair, blunt bangs, purple eyes, double bun
Outfit: purple headwear, mob cap, bun cover, vertical-striped dress, purple dress, long sleeves, robe, wide sleeves, red bowtie, neck ribbon, red ribbon, white footwear, shoes
Accessories: crescent hat ornament, crescent hair ornament, red bow, blue bow, hair bow, hat bow, footwear bow
- "Mukyuu", a nonsensical catchphrase attributed to her
- Voile, the (unofficial) name generally used in reference to the mansion's library, which Patchouli tends
- Catchouli, a disgustingly adorable chibi cat girl version created by Hazuki Ruu
- Patchoung, a version of her created by Aoshima