Mumei is a member of the Council and the Guardian of "Civilization", a concept crafted by mankind.
As a living embodiment of the sum of mankind's efforts—the mark that humans have left on the world—she is far removed from her fellow members, as well as other lifeforms. Due to not being created by the Gods, she was free to choose her own appearance, and decided to make herself owl-like, after the bird that symbolizes wisdom.
She is gentle, wise, and an unbelievably hard worker. As a well-traveled vagabond, she is blessed with a wealth of knowledge of the world. She has seen, heard, and experienced so many things that she has forgotten most of them.
For some reason, she seems to project a rather pitiable aura. Perhaps this is in part thanks to the loneliness she has often felt in her perennial travels.
Nanashi Mumei has golden-brown eyes and long, brown ponytail hair with a pair of feathers atop her head. She dresses in a brown cloak secured with a ribbon. Mumei also wears gloves that are fingerless on her index and pinky fingers. She has a belt wrapped around her waist with a lantern, pouch, and small dagger around it. Below her outfit is a pleated skirt. She has leggings with her right leg reaching above her thighs and the left leg below her thighs, and wears brown boots. Friend flying beside her is a paper bag with a drawn mouth and a plaster shaped like a cross on his face.
In the beginning, Mumei gave the impression of a cheerful, gentle girl who is soft-spoken and somewhat innocent, especially when compared to her peers. She was initially very shy and often visibly nervous during streams.
However, as she has gained confidence in streaming, a different persona has emerged. Mumei’s streams are now characterized by the duality between a relatively low energy, relaxing, and comfortable tone to another side which is more spontaneous and energetic; with her often demonstrating psychopathic tendencies in these moments. Though the disparity between her macabre thoughts and cute voice surprised many at first, the line separating these two sides has since blurred to a point of seamlessness – with Mumei’s appreciation of the grotesque and ‘cursed’ being wholly embraced by her fans today.
Despite this, she can be rather emotive, and is known for her hearty wheezing laugh, which is often heard during collaborations with her colleagues due to her tendency to laugh at nearly anything she says. She often vocalizes and hums randomly, which has been compared to bird chirps or "birb noises". She's also somewhat scatterbrained, and has a tendency to forget things easily.
At debut, her colleague described Mumei as having the cutest voice in Hololive -Council-, though she has also demonstrated a rather unexpectedly wide vocal range, along with a tendency to emit high-pitched screeches when surprised or agitated.
Her fans and even other members of hololive have developed some degree of protectiveness for her, due to her soft nature giving a "little sister" vibe, though Mumei's later behavior would eventually create uncertainty as to who needs to be protected from whom.
Mumei is also associated with the simple text emoji :D due to her regular use of it in her stream descriptions.
She has the ability to take the form of an owl. She claims that switching forms too much in the past turned her brain more bird than human, resulting in her memory problems.
Mumei likes: obtaining knowledge, vegetable broth, drawing stuff, and singing. She has a fondness for berries.
She dislikes: forgetting things, mud, printers, and mosquitoes.
Mumei is mostly timid around new people, but will quickly show her smug and arrogant side once she get to know them.
Mumei is very submissive, but is very enthusiastic during romantic encounters.
She playfully teases and taunts her lover in bed.