Kigaan was a Youma (Negaverse monster) who worked for Jadeite (Jedite) as part of his quest to gather human energy to awaken Queen Metallia (Negaforce). She appeared in episode #10 disguised as a stern looking bus driver with her hat pulled low over her eyes.The bus that she drove was meant to collect the girls who had come from the Hikawa Shrine (renamed Cherry Hill Temple in the dubbed North America version of the anime), where they had purchased the good luck charms charged with dark energy from Jed (one of Jadeite's aliases) the caretaker of the Shrine, but the charms once activated by Jadeite caused the girls to fall into a trance-like state. The girls would then board the route 66 bus near Sendai Hill (which was being driven by Kigaan). The bus then floated through a black hole in the sky once the girls became unconscious from the cursed good luck charms. Once on the other side of the dimension, Kigaan collected their energy for Jadeite. After initially being too scared to get on the bus due to Kigaan's scary appearance, Usagi (Serena) Tsukino managed to board the same bus with Luna, this time disguised as a bus attendant. Once on board the bus, she discovered its passengers to be unconscious and demanded the bus driver to stop. Bus driver Kigaan refused and instead transported Usagi (Serena) Tsukino, Luna and the unconscious passengers to the other dimension. Meanwhile at the Hikawa Shrine, priestess Rei (Raye) Hino learned of the bus that recently disappeared and discovered Jadeite scheme. When she confronted him, Jadeite opened a black hole which sucked Rei (Raye) Hino and her two pet birds (Phobos and Demos) through to the other dimension. In the other dimension, a crying Usagi (Serena) Tsukino witnessed Rei (Raye) Hino topple into the dimension and being caught by Kigaan before changing into her true Youma form. Whilst holding Rei (Raye) Hino hostage, Sailor Moon attempted to attack Kigaan with her Moon Tiara but Kigaan dodged the Moon Tiara whilst holding Rei (Raye) Hino in a headlock. Phobos and Demos, who had also come through the same black hole as Rei (Raye) Hino, began pecking Kigaan, forcing her to release Rei (Raye) Hino. After shooing the birds away, the Youma caught Sailor Moon's Moon Tiara in her hand. This was evidently what Sailor Moon had planned, because Sailor Moon ordered the tiara to wrap around her, temporarily incapacitating her arms and torso and giving Rei (Raye) Hino just enough time to transform into Sailor Mars for the first time and defeat the youma (Negaverse monster) with her Fire Soul (Mars Fire Ignite) attack. After her defeat, the back hole that the buses, Usagi (Serena) Tsukino, Luna and Rei (Raye) Hino came in was closing up. Sailor Mercury used her power to keep it open and Tuxedo Mask safely returned the buses and the unconscious passengers back to Sendai Hill.TriviaAlthough Sailor Moon and Sailor Mars (and at one point, Sailor Mercury) combine their attacks several times in the series, Kigaan is one of the only three Youmas (the others being two of the Doom and Gloom Girls) to be individually killed by Sailor Mars.