Koan

Her villain design borrows almost entirely from the manga, letting go only of the rose corsage at her neck. She wears a striped pink bodysuit beneath a fluffy purple tutu with blue heels, and a blue gem rests above her brow next to the Black Moon crest shared by every member of the clan. Wavy dark purple hair spills down her back, pinched into two upward points. Once Sailor Moon heals her, the crest fades and she trades the costume for ordinary clothes, most often a black sleeveless turtleneck, a long light purple skirt, and black flats.

Vanity and ambition mark Koan more sharply than any of her siblings, and the anime hands her the fullest arc of the four. She fusses endlessly over her face, laments her looks, needles her older sister Calaveras, and shops for fresh cosmetics and clothing whenever she passes among humans. Her grand daydream is to reign over Crystal Tokyo as its queen with Rubeus crowned at her side, a fantasy fed by her certainty that he loves her back, something he never bothers to correct. Being the first sister to appear, she throws herself hardest into tracking down Chibiusa, and every failure only hardens her drive to kill the child and earn Rubeus's affection. Unlike Berthier, she shows little deference toward her elders.

Koan is the first Spectre Sister to face the Sailor Guardians, opening with a burst of Dark Fire. Their paths cross four times over. She first tries to seize Chibiusa for Rubeus and is beaten off by Sailor Moon's scepter. Next she moves against a crystal point at the Hikawa Shrine with the help of her Droid, Dumbull, whose victims fall under her spell, only for Sailor Mars to burn her back. In a third meeting she and her sisters retreat once Sailor Moon topples Rubeus. Sent again to claim the shrine, she offers Rubeus a cologne that he crushes without interest, though a passing compliment convinces her he still cares. While pursuing Chibiusa she battles Rei and Yuuichirou, who leaps in front of her flames; Rei then transforms, and with Tuxedo Mask's aid Sailor Mars defeats her using Burning Mandala. Rubeus promptly discards Koan for her failures and casts her off the team. Furious, she goes on a rampage, but Sailor Mars shields her from Sailor Jupiter and coaxes her toward good, after which Sailor Moon's Moon Crystal Power clears away the last of the darkness inside her. Reborn, Koan opens a cosmetics shop, later helps turn Berthier good, and in the end the four reunited sisters run a cosmetics stand together.