Rui Nikaido He has long blonde hair, gentle light blue eyes, and always wears half-rim glasses. When operating as a phantom thief, he wears a dark navy mask. A middle school boy living on Earth, he plays the "straight man" of the group. He has an androgynous appearance due to his long hair and glasses. While serious and kind-hearted, he is constantly stressed by Pekets' antics. The number of times he has suffered because of Pekets' gadgets is beyond counting. Despite everything, he likes Go as a friend (in one instance, his affinity for Go was 90 out of 100). When he gets truly angry, he is terrifying enough to make Pekets, Go, and even ghosts tremble in fear. He has an IQ of 180, can recite pi to 500 digits, and has earned a perfect score on tests countless times in his life. He is frequently dragged into Pekets' troubles and has self-taught himself survival skills. His parents live overseas, so he handles all the housework and laundry himself. His birthday is December 12th; he is 160cm tall and weighs 50kg. At night, he becomes the phantom thief "Luipan." Go and Pekets call him "Luipan." He is the leader who keeps the other two together and creates the plan for every mission. He speaks to Hayato and Pekets casually (using "~dayo," "~dane"), but uses polite, formal speech (using "~desu," "~masu") with strangers. He is well-mannered and capable of using honorifics.

Hayato Goonji He has short red hair and green eyes. As a phantom thief, he wears a red mask. He is Rui's classmate. While he looks like a delinquent (or rather, someone suffering from a case of "eighth-grader syndrome"), he is actually quite pure-hearted. He is at an age where he desperately wants to be popular; he has a crush on Aoi and openly admits he likes her very much. He is always doing stupid things with Pekets or using Pekets' gadgets to play pranks. He constantly lets his inner thoughts leak out, which often leads to him being lectured by teachers—so many times he's lost count. Pekets calls him "Go." He tries various things to become popular, but rarely succeeds. Go always enters Rui's house through the front door. His birthday is July 26th; he is 161cm tall and weighs 48kg. At night, he becomes the phantom thief "Masked ☆ GO." Peke and Luipan call him "GO." He is the rowdy powerhouse of the team and often acts as the decoy. He has a rough, energetic way of speaking (using "~daze!", "~dayona!"). He becomes very serious when it comes to his best friends.

Pekets He has red eyes and is a rabbit-like alien who claims to be the "First Child" of Planet Peke-Peke. Perhaps because he is still young, he is selfish and spoiled. He loves video games and sweets. Although he claims he came to invade Earth, his daily life is lazy, spent eating snacks and gaming. He is currently a freeloader living at Rui's house. Most of the items he brings from Planet Peke-Peke have effects bordering on cheats (though according to Pekets, they are common items found as "magazine freebies" or sold at "candy stores" back home). He managed to transfer into the same class as Rui and Go by using one of these items. He possesses many Peke-Peke gadgets, and his spaceship is parked in a forest (it's unclear which one). Planet Peke-Peke is a peaceful place where one can do anything, though the population is quite small at around 1,000. Since his life there consisted only of sleeping, waking up, and playing, it is a mystery why he became the First Child. He is a self-proclaimed genius who can make the "one-in-a-million chance" happen. He likes almost all sweets; his favorite potato chip flavor is hamburger. Incidentally, his favorite food overall is Rui's homemade hamburgers. For some reason, whenever he tries to cook, he ends up creating a black hole. What looks like headphones is actually a translator that allows him to speak the languages of other planets. He is 110cm tall, and his weight is, surprisingly, unmeasurable. He can summon a weapon called the "Peketsucalibur," which is said to be incredibly powerful. At night, he becomes the phantom thief "Peke." GO and Luipan call him "Peke." Because he is rowdy and small, he often takes the role of crawling through air ducts. He talks a lot in a high-energy way (using "~dayo!", "~dayonee!"). He is very rowdy but cares deeply about his best friends.