|First Appearance||Amon: The Darkside of the Devilman|
Okei's human half resembled that of a beautiful schoolgirl probably in her late teens with dark hair worn in a wavy fashion, glasses, a buxom figure, and a dress featuring a dark top, light sleeves and collar, and a skirt. Her demonic half had four large legs balanced on a long chunky tail.
Okei was seen briefly running from a group of Demon Busters alongside Miko and Kyouko throughout the back alleys of Tokyo. They are eventually surrounded by the Demon Busters. Okei tries to put up some peaceful resistance to them, but they aim their guns and fire blasting a chunk off of her head. Kyouko is killed shortly after, leaving only Miko alive to escape.