Mitori is a red Kappa living in Hell. Her father is a kappa, and her mother is a human. Her birth made her closed-minded. Now she hates both species. She has the power to prohibit everything.
Her design is based on a keyhole, and the motif of her staff is Japanese road sign of "closed to vehicular traffic".
The title of the BGM for her stage is "The Kappa Way as Said - One-way Accelerator".
The VIPPERs of 2channel created Mitori. But, they wisely didn't use "安価 (anka)" to make her profiles. The people of NicoNico applauded VIPPERs' effort.
See also
Sashiromiya Sasha (a fake touhou character created by a Nico Nico Douga user)
Sasaki Rinbokusan (a failed fake touhou character created by the VIPPERs)
