- Alien Girl (宇宙人少女 Uchujin Shojo)
- Ultra High-civilized people (超高度文明人 Kodo bunmei jin)
Originally said to be the race who sent Mienin and their bio-controllers to Earth. Months later, they sent one of them, Mitoru to Earth with a bio-control crown to kidnap a Mienin to become Gamoran. Once at Kapuya Island, Lidorias saw her floating orb, but was put to sleep and moved forward. Musashi and a researcher found the orb taking one of the monster and Mushashi to a different location. Once there she explained her plan as a "Final Test" for humans and put the controller on the Mienin and became Gamoran II. After freed from the aliens power, Musashi became Ultraman Cosmos and battle the monster. After freeing it, Mitoru leaves earth, knowing that humans have passed this "test".
- Cast: Hitomi Akimoto
- Mitoru's name was never revealed in the series as she was credited as Space Girl (宇宙少女 Uchū shōjo) until the Tsuburaya All Monster photobook was released.
- Height: 135 cm
- Weight: 32 kg
- Origin: Space
- Powers and Weapons
- Bio-Controller: Mitoru possess a Bio-Controller that can turn Mienin into Gamoran. But unlike normal Bio-Controllers, her version only turns Mienin into a different Gamoran which looks like a giant version of Mienin instead of bearing spikes on his shoulders.
- Orb: Mitoru can travel to different places in a yellow orb. She can also contain others in this orb. Should there be not enough space, Mitoru can enlarge the size of the orb.
- Sleeping Ray: Mitoru can fire a sleep ray from her hand to put monsters to sleep. It also can be fired when she is in her orb form.