She originally lived with humans in a city named Sado. Mamizou often lended them money and got along with them well. However, she doesn't get along with foxes and there are no foxes in Sado.
She currently lives in Myouren Temple, along with Nue Houjuu.
In Hopeless Masquerade, she plays a key role in helping all of the characters. As the penultimate boss of each character's route except her own, she directs each character to the source of the problems. Before her route, she directs each character to Hata no Kokoro. During her own route, she helps Kokoro by steering her in the right direction for creating her own unique personality. In Kokoro's route, Mamizou directs Kokoro to the final four-way fight with Reimu, Byakuren, and Miko.
- (Touhou 13) Has brown fluffy hair with a green leaf on top. Has ears and a tail like a Tanuki would have. Wears round glasses and two black bracelets. Her top is brass and has a notepad of confidence and a bottle of 酒 sake that represents virtue. Has pink shoulder caps. Her skirt is maroon with brass patterns. She has brownish sandals.
- (Touhou 13.5) Same as above, except her leaf is larger and has bells, and her glasses are white.
Mamizou, proud of her race's esteem, is good natured, albeit with a mischievous streak. She speaks the way an old lady might, and occasionally squints as if she was nearsighted. She isn't one to take a grudge, but as Marisa in her extra stage shows she has her limits of niceness. She does enjoy pulling pranks on humans and watching them be confused and flustered.
Despite being brought in as a 'trump card', she is noted to being friendly with humans, and has been seen taking on the form of a human while in the Human Village. Though she is seen in the Human Village often in human form, Symposium of Post-mysticism has stated that she does not make an effort to hide her tail, considering it a mark of her high status.
- Nue Houjuu (Friend)
- Byakuren Hijiri (Currently lives at her temple)
- Ran Yakumo (Enemy)
- Kosuzu Motoori (Admirer)
- Hata no Kokoro (Known)
- She is a second character that is a meganekko in the series, the first one being Rikako Asakura. However, she is the first one to wear glasses in a Windows game.
- Futatsuiwa (二ッ岩) means "Two Rocks". Her first name Mamizou is written in katakana. This may be a pun on how tanukis are often represented in folklore.
- Her hometown may possibly be the real life town of Sado in Niigata Prefecture.