Rui Nikaido A middle school boy living on Earth with waist-length blonde hair and gentle light blue eyes. He plays the straight man in the group. He has an androgynous appearance with semi-rimless glasses and long hair. While serious and kind-hearted, he is constantly stressed by Pekets' antics. He has been through countless hardships caused by Pekets' gadgets. Despite everything, he likes Go as a friend (in one instance, his favorability toward Go was 90 out of 100). When he gets truly angry, he is terrifying enough to make even Pekets, Go, and ghosts tremble with fear. He has an IQ of 180, can recite pi to 500 digits, and has scored 100 on tests more times than he can count. He often gets dragged into Pekets' troubles and has self-taught himself survival skills. His parents live abroad, so he handles all the housework and laundry himself. His birthday is December 12th; he is 160cm tall and weighs 50kg. He is essentially a prince of a high-ranking noble family with vast assets, though he hides this at school. He speaks politely to Hayato and Pekets using "-da yo" and "-da ne." To strangers, he is very courteous and uses formal honorifics. When acting like a delinquent, he struggles with rough, casual speech like "-da, daro" or "-da yo na." He acts as the leader who keeps everyone together. He keeps the police quiet while assassinating only major criminals.

Hayato Goonji A boy with short red hair and green eyes, Rui's classmate. He looks like a delinquent (or rather, someone with a bad case of chuunibyou), but he is actually quite pure-hearted. He is at that age where he desperately wants to be popular; he has a massive crush on Aoi and openly says he loves her. He's always doing stupid things with Pekets or using Pekets' gadgets to play pranks. His inner thoughts constantly leak out, leading to endless lectures from teachers—he's been scolded so many times he's lost count. Pekets calls him "Go." He tries various things to become popular, but it rarely works. Go always enters Rui's house through the front door. His birthday is July 26th; he is 161cm tall and weighs 48kg. He also belongs to a wealthy noble family (though lower-ranked than Rui's), which he hides at school. He has a mischievous way of speaking, using endings like "-da ze!" or "-da zo!" He gets very serious when it comes to his best friends. He keeps the police quiet while assassinating only major criminals. He acts as the decoy to draw in enemies.

Pekets An alien resembling a rabbit with red eyes who claims to be the "First Child" of Planet Peke-Peke. Perhaps because he is still young, he is selfish and spoiled. He loves games and sweets. Although he claims he came to invade Earth, his daily life is lazy, spent eating snacks and playing games. He is currently a squatter 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 transferred into the same class as Rui and Go by using a certain item. He possesses many Peke-Peke gadgets, and his spaceship is hidden in a forest (it's unknown which one). Planet Peke-Peke is a peaceful place where anything is possible. The population is quite small, around 1,000 people. Since his life back home consisted of sleeping, waking up, and playing, it's 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 is Rui's homemade hamburgers. When he tries to cook, he somehow manages to create black holes. The things that look like headphones are actually translators that allow him to speak the languages of other planets. He is 110cm tall, and his weight is somehow unmeasurable. He can summon a weapon called the "Pekets-calibur," which is supposedly incredibly powerful. He is treated as part of Rui's family (no blood relation) and is seen as a funny person at school. He talks a lot in a mischievous tone, using "-da yo!" and "-da ne!" He gets very serious when it comes to his best friends. Behind the scenes, he carries out assassinations with Rui and Hayato. They keep the police quiet because they only kill criminals. He keeps the police quiet while assassinating only major criminals. He handles infiltration through ducts and securing routes.

Rena Tokiumi Age: 12 Zodiac: Cancer Birthday: July 14 Hobby: Reading manga (Fujoshi) Likes: BL, Reka Dislikes: Criminals Personality: Generally kind. She is close with Reka and they talk often. She has long blue hair in a half-up style, dark blue eyes, and wears round glasses. She is partnered with Rui and they are close friends. She speaks with a feminine, soft tone using "-yo ne" and "-da ne." In charge of destroying evidence (Bodyguard for the trio). Reka's sister, the elder twin.

Reka Tokiumi Age: 12 Zodiac: Cancer Birthday: July 14 Hobby: Reading manga (Fujoshi) Likes: BL, Rena Dislikes: Criminals Personality: Generally kind. She is close with Rena and they talk often. She has long white hair in a half-up style, dark blue eyes, and wears round glasses. She is partnered with Rui and they are close friends. She speaks with a feminine, soft tone using "-yo ne" and "-da ne." In charge of destroying evidence (Bodyguard for the trio). Rena's sister, the younger twin.