Koan is the youngest of the Ayakashi Sisters who accompanied Rubeus to 20th Century Tokyo in order to look for Chibiusa and the Silver Crystal. This is the original depiction of the character created by Naoko Takeuchi.
Koan has wavy dark purple hair that falls down her back and dark purple eyes. She wears a pink pinstriped onesie, a dark purple tutu and dark purple heels. She also wears a black rose corsage around her neck and an identical ring on her right hand.
Black Moon Arc
Koan first appeared in Act 15 of the manga, where she was in charge of Operation 001: Operation Recruit. Disguising herself as a T*A Academy for Girls student named Koan Kurozuki, she recruited people to the Black Moon by foreseeing their deaths and then promising a peaceful passing if they joined her. Unfortunately, those who agreed bore a crescent sign that would then spontaneously combust, as they were most likely unable to handle the power.
After finding one of the school's teachers who had suffered this fate, Sailor Mars confronted her, but was trapped in Koan's flame barrier. Though Sailor Moon used her new Cutie Moon Rod to destroy Koan with Moon Princess Halation, she was unable to break the flame barrier, and Sailor Mars was abducted by Rubeus.
Koan in the fight uses the Dark Fire to create streams of fire, flaming barriers and setting fire to people and objects such as Sailor Moon's tiara. She can also use her fire to trap her opponent in a sphere of flame.
Koan is named after Kooankou (紅安鉱), a mineral that is also known as Kermesite and Red Antimony. The "Kermes" part of Kermesite means "Crimson." The Kanji character that is missing is the character for a "mineral" or "ore." Kermesite is found in chocolate as well as other places.
Her given human name in the Japanese manga is Koan Kurozuki, with her last name meaning "black moon".
Her Dic and Tokoyopop name Catzi/Catzy could be because she has a hairstyle which resembles cat ears. Her old dub name name Catzy which could also sound like Cat could be in contrast to Berthier's dic name Birdy/Birdie, which both names indicate "cat" and "birdy".
- She is the Ayakashi Sister equivalent to Sailor Mars.
- In the Materials Collection, her ideal voice was described as a sexy adult-sounding voice
- In the German translation of the manga, both Calaveras and Koan stated to be the youngest sister.
- Koan appeared in chapter four of the video game Sailor Moon: Another Story,and she been turned evil again, along with her sisters. She was the first to attack the Senshi on the Black Moon UFO. However, instead of being healed, she was killed by the Sailor Senshi. She used the attack Dark Fire.