apartment next to Go's room. She became Jirō's caretaker after the deaths of the Sakata elder siblings and providing the young boy with moral support. She also harbored an affection for Go and learned of her crush's double life as an Ultraman in the final episode. Alongside Jirō, Rumiko returned in episode 10 of Ultraman Ace. She is portrayed by . Monsters and aliens Aliens : The first alien to appear in the series, his mission is to kill Ultraman Jack on Earth. He assumed the human form of a deaf young boy named , using his friendship with Ibuki's daughter, Minako, to infiltrate MAT headquarters. Zeran made himself known to Go using a special telepathy, putting the officer in a psychological warfare situation when his claims fell on deaf's ears. With his controller, Zeran manipulated the space monster Plooma into fighting Jack, but his true goal was to hijack the Ultra Bracelet against its wearer. Ibuki managed to locate Teruo at a morgue where he killed the boy in a gunfight, revealing Teruo's true form upon death. Despite Go's insistence to cover Teruo's disappearance from Minako, Ibuki was against it after his experience from being deceived by an alien. Alien Zeran is voiced by , while Teruo is portrayed by . : A white alien who assumed the human form , his main ability is telekinesis, allowing him to bury Muruchi and his spaceship underground. A year prior, his arrival on Earth was to investigate the planet's suitability with his own kind but constant pollution deteriorated his health and making it harder to locate said spaceship. He discovered the orphan Sakuma and came to treat the boy like his own son. Due to his attempt in protecting the boy, Mates was killed by a policeman from the townspeople's anti-alien sentiment group and this resulted with the release of Muruchi. As revealed in Ultraman Mebius, this particular Mates had a son named Bio. In his human form Kanayama, he was portrayed by and named after a common surname used by native Korean in Japan. In the flashback scene of Mebius, he is portrayed by . His death was written by Shozo Uehara as a nod to the discrimination of Koreans during the Kantō Massacre. : A vampire bat alien who planned on eradicating mankind by killing young women. His method was done by assimilating with the corpse of and targeted