Member of the Black Moon
Koan has long wavy dark purple hair, which she wears down except for two knots and she wears a large jewel as a head piece. Her outfit is a tight purple dress with dark vertical stripes with a dark purple tutu and dark purple heeled shoes to match. She has the symbol of the Black Moon clan on her forehead. She also wears a black rose corsage around her neck and Black Crystal Earrings. She has her nails painted purple.
Koan appears in Act 15, where Rubeus gives her Code 001: Operation Recruit to convert humans to their cause. She poses as a student at T*A Girls Academy, where Rei Hino attends and becomes the leader of the supernatural club, the Black Moon. Koan sets up a fortune telling booth and tells her clients about how they will die. Koan then reveals her true self and traps Sailor Mars in a flame barrier. She is killed by Sailor Moon, but Sailor Mars, is still trapped in Koan's fiery shield, after Rubeus takes her.
Koan can use the power of fire similar to Sailor Mars, however hers are a dark shade of blue.