Lunar Envoy An envoy who came with Eirin to pick up the Princess and return her to the moon. Instead, she was betrayed by Eirin and became the latter's first experimental subject on Earth. She has the best chassis by far, so Eirin managed to impart the Lunatic Eyes and time manipulation abilities on her. Yet, the ease of how her memories was initially erased ironically caused her memories to resurface and her subsequent rebellion against Eirin. That incident provoked the wrath of Eirin, so she was killed. Since she was deemed a failed product, her body was tossed into the mountains, a veritable den of youkai.

Yagokoro Eirin (clone) Having become tired of managing her clones in the underground complex, Eirin made a clone of herself. Some subtle modifications on the clone were made such that its abilities can not match up to the original. The clone did not notice. Later, the clone managed to rebel and supplant the original Eirin. Still, her heart remained in fear. Despite being successful in powering herself up, the clone can never attain the same abilities as the original.

Medicine Killacholy Also known as Killer Medicine. The result of the mechanization of Medicine's empty body. She's a fearsome weapon, and possesses virulent poison and a laser sword. Medicine's real body is Su-san. Unlike the original, Killer Medicine can still move as long as both cores are not destroyed. Creating such a hideous product is beyond the knowledge of the original Eirin. Her creation reflects the depraved state of mind of the clone Eirin. Killer Medicine's poison did not affect Udonge in the main story. Her creator, the clone Eirin, had subtly modified her poison to be ineffective on clones so that she would remain unaffected as well.