Third-year student at Central Tanegashima High and the main character of the series. He's the second half of the Robot Research Club. His lackluster, indifferent attitude results in people considering him unreliable. A dedicated fighting game otaku who is currently ranked fifth in the world in Mobile Battler Gunvarrel Kill-Ballad ONLINE (KB), a robot fighting game. His goal is to become #1 in KB. Despite being part of Robot Club and playing KB, he has zero interest in robots.

The only time he gets serious is during a competition. Whenever anyone asks for a favor, he childishly demands they beat him in a match of KB first.

His attitude drastically changes when it's about winning; he hates to lose. His childhood dream is to become an astronaut.

Third-year student at Central Tanegashima High, president of the Robot Research Club and Kaito's childhood friend. She is the positive, hyper, and reckless type who often gets carried away. Her goal is to finish the giant robot that her older sister Misaki Senomiya, who founded the Robot Research Club, created. She works hard to reach her goal.

She's obsessed with a character from a famous robot anime and quotes him all the time, putting on a pair of red-framed glasses whenever she does so. However, her eyesight is totally fine.

An active otaku addicted to moe in both its 2D and 3D forms. His nickname is Daru.

His imagination runs a bit wild and he isn't scared to talk to girls, having strong communication skills though he sometimes speaks in dirty jokes and internet slang. He's friendly with everyone, though he never shows his real self.

Even though he jokes around, he actively helps people whenever he can. Deep down, he loves his beautiful wife and his daughter, who's about to turn three. He complains a lot, but he's the type who can't say no when someone asks nicely. He spends his days as a phenomenal hacker in Tokyo known online by the famous pseudonym: "DaSH (Daru the Super Hacker)." He claims he's just visiting Tanegashima as a tourist, but in reality...

Second-year student at Central Tanegashima High. His overconfidence and vast knowledge of robot science makes him act arrogantly even to his elders. He has many fan girls thanks to his handsome looks and cool demeanor, but due to his stoic personality he is not used to interacting with girls.

He bumps heads with Akiho often as she loves Gunvarrel-type robots and he prefers realistic robots. He also has a tense relationship with his father, who hates robotics.

Contrary to his cool demeanor, when he gets nervous he starts sweating and slurring his speech.

Third-year student at Central Tanegashima High. A cute, puppy-like karate girl. While cowardly and easily teary-eyed, she has the inner strength to care for her whole family by herself. She's a hard worker, but her self-doubt has held her back from obtaining a black belt. She has never won a single official match.

She likes urban legends and collects all sorts of rumors about them. Sometimes she investigates urban legends herself, sneaking out to locations where they're said to occur. However, she cannot handle occultic stories and is terrified of ghost stories.

She is always in need of sleep due to cooking breakfast, lunch, and doing house work late into the night for her family. If she's not careful, she can fall asleep anywhere.

A negative, bad-mannered, shut-in otaku who uses outdated internet lingo IRL. She's a programmer who created Mobile Battler Gunvarrel Kill-Ballad ONLINE, a robot fighting game which boasts over 20 million users. She meets Kaito through KB, but otherwise has no interest in human interactions. She doesn't even try to listen to people unless they grab her interest.

She likes fantasizing about boys' love and reads old doujinshi while creepily laughing.

A tidy and proud little girl. The younger sister-type, she tends to be very proper yet still has an innocent childishness. She calls Kaito "Big Brother" and cherishes him. She doesn't know how to doubt others and sulks when she's treated like a child.

Sometimes her personality seems to mysteriously change and she becomes emotionless. She appears to have a deep connection to the Kimijima Reports.

A researcher on a long-term business trip from JAXA Chofu Space Center to Tanegashima Space Center (TNSC). She has an easygoing, innocent personality and is always smiling, though at times she can make blistering remarks. She doesn't care what she has to do to get what she wants. Due to her behavior, she's known as a "Rampaging Beauty." She gets upset when people say she has soulless eyes.

Akiho's older sister who created the Robot Research Club while attending Central Tanegashima High School. She graduated from a university in Japan and works as both PR and a test pilot at Exoskeleton Company, a global robot development enterprise. Her beautiful looks and lovable personality gives her an idol-like following.

A teacher at Central Tanegashima High and supervisor for the Robot Club. He's former classmates with Misaki and Mizuka, and was the first president of the Robot Club. A complete muscle head, he doesn't understand scientific or difficult things. He believes there's always a way to make something happen. He gives lengthy lectures, but not in an awful way. He acts like a know-it-all and loves to offer "Pro Tips."

Stubborn, grumpy and hard to interact with, the island's famous old man runs the Robot Clinic, where he repairs both hobby and life-size robots for a living. He rents out equipment to the Robot Club upon request and loves listening to rock music and wearing leather jackets.

A graduate from Kaito's high school who was once part of the surfing club. She has a laid back, boyish personality and acts like a big sister to Kaito. She can be rather scary when she's mad. She supervises the Irei General Store located near school. She and Misaki were good friends in high school, and she keeps an eye on Kaito and Akiho.

An executive at Exoskeleton Company and Misaki's boss, chief of HUG text operations. He always appears calm with a neutral expression. It's impossible to tell what he is thinking.

The man who left the Kimijima Reports all over Tanegashima. He appears well-mannered and has a calm way of talking, but everything else about him remains a mystery.

Mitsuhiko Nagafukada's uncle and CEO of Space Candy, a candy company in Tanegashima. The hearty type who doesn't think too deeply, he is believed to have amazing business skills, but mostly it's just from following his gut feelings. He became the sponsor of the Robot Club when they were having trouble with funds.

Subaru's dad: an old-school, stubborn man. He makes a living as a fisherman and is part of the Tanegashima Fishermen's union. Usually he is quiet, but he can get violent when he is angry.

As Vice Principal at Central Tanegashima High, she holds high expectations for education. She usually puts students first, but can be rather hard on those that do not match her perception of an ideal student. She feuds with the Robot Club over its funding.

The father of Akiho and Misaki, and director of JAXA Tanegashima Space Center. A tranquil man who does not like to argue. He loves robot anime and plastic models, and was a major influence on both of his daughters' love for robots.

A mysterious figure who won back-to-back hobby robot tournaments in Tokyo. His real identity remains a secret.

A mysterious new star that arrived at the Battle Robots festivities held in Tanegashima. A mask covers her face, keeping her real identity a secret.