Our main character. A lazy member of the Robot Club, he is Akiho's childhood friend who is always seen playing Kill Ballad game which he ranks fifth in the world. His role in the club is Tanegamachine-3's operator and later, the pilot of Gunvarell.
Catch Phrase: "...but you'll have to beat me in Kill Ballad."
The President of Tanegashima High's Robot Club which her sister, Misa, founded. Very energetic and optimistic, Akiho's goal is to finish Gunpro-1 project, a project to build a real-life Humongous Mecha the club started eight years ago.
A-Cup Angst: Implied to be the reason she hates when Mitchie calls her "Little".
Always Someone Better: A gifted roboticist, but firmly believes her skills pale in comparison to her older sister's.
Humble Goal: Wants to finish constructing the Gunvarrel robot her sister started.
Ill Girl: She suffers from "Elephant Mouse Syndrome" which makes her perceive a few seconds over the course of 5 minutes, leaving her in a comatose state if she overexerts herself. This condition was caused by some kind of accident nine years before the main story starts.
A second-year student in the same school as Kaito and Akiho. A brilliant roboticist, Subaru's skills allowed him to win the Robo-One championship, but did so under the disguise of his "Mr. Pleiades" persona so his father would not be upset with him. Kaito later blackmails him to join the Robot Club.
Abusive Parents: His dad will get rough with him if he shows signs of going down any career path besides taking over the family fishing business.
A dual program within the IRUO app, acting as the AI interface. She dictates everything about the Kimijima Reports, from its instructions to the actual details, even though she really doesn't know what they actually mean. Geji-nee is the main AI, and she's the one who makes the actions. Airi is actually a Littlest Cancer Patient given extra time to live her life by Kou Kimijima.
Artificial Human: She's an AI that can only be seen by using the iPod-like devices that act as phones and the consoles everyone plays Kill Ballad on.
A member of the Robot Club who practices Karate. Junna was initially reluctant to join due to being afraid of robots, though was encouraged to join by Kaito. Her fear was caused when a robot nearly crushed her as a child. She is also the granddaughter of Fujita.
Local shut-in and the socially inept creator of Kill Ballad, the wildly popular video game adaptation of the Gunvarrel anime. A brilliant programmer, Frau is the daughter of the Director of Gunvarrel, who was accused of murdering the entire Gunvarrel staff although the details of which are even more complicated. Her mother disappeared shortly after and Frau has been searching for her since.
Ambiguously Bi: Kisses Kai at one point and is constantly gushing over Airi and Jun.
Anime Hair: Her pigtails defy gravity when they're tied up.
The previous leader of the Robotics Club, Misaki now works for EXOSKELETON as the company's spokeswoman and investigates the Kimijima Reports behind the scenes. Once an idealistic and energetic girl, Misaki has grown aloof and detached, never even keeping in touch with her sister, Akiho. Misaki murdered Kou Kimijima after learning of his genocidal plan. She would later be possessed by Kimijima's cybernetic ghost, becoming a pawn in the scheme she tried so desperately to prevent.
The Ace: While in high school, Misaki was an extremely skilled roboticist, a talented engineer, won the Robo-One tournament, and regularly defeated a young Kaito at video games.
Irei is the owner of a local convenience store and is a motherly figure to Kaito and Akiho. Mizuki is very knowledgable about Tanegashima and various rumors that circulate the island. Her legs were paralyzed from a motorcycle accident, and, some time later, was given prosthetic robotic legs from Misaki.
Blood from the Mouth: Happens when the robotic exoskeleton that helps her walk goes out of control and forcibly straightens her spine up.
The grandfather of Junna who runs the local robotics shop. He supplies the Robotics Club (both past and present) with the parts they need. His expertise in creating robots is one of the greatest. He also loves blasting Heavy Metal in his shop.
A teacher from the main characters' school and the advisor of the Robotics Club. Mitsuhiko was himself once a member of the Robotics Club alongside Misaki. He's a jolly guy, though he rarely gets any respect from Akiho due to his... lazy habits.
Voiced By: Tetsuo Kanao (Japanese), David Wald (English)
Mitsuhiko's bulky uncle and the president of Space Ame, the company that makes the ''Space Candy" Kaito is so fond of. Sumio funds the Robotics Club's projects in exchange for publicity and Space Ame's logo is displayed on the club's robots.
The mysterious CEO of EXOSKELETON, the company that develops Power Suits among other robotic projects, and Misaki's supervisor. Sawada is also a member of a secret organization that opposes the Committee of 300 despite Sawada being the son of one of the committee.
Archnemesis Dad: Will not rest until he has stopped Project Atom and the Committee of 300, which includes his father.
The author of the Kimijima Reports, who died several years ago.It turns out that he works for the Committee of 300 and caused the Anemone-gou incident which was in fact an experiment that would have killed all the test subjects; This was stopped by Misaki who killed him. However before his death he uploaded his consciousness to the internet and lives on through Iru-o, and now plans to execute the Committee's plans by inducing a massive solar flare that will kill the majority of the population of Earth. He uses the Kimijima Reports to manipulate people, and he has Geji-nee and Misaki (who was brainwashed by him) do his bidding in the the virtual and real worlds respectively.
Cybernetics Eat Your Soul: Airi mentioned that he wasn't always obsessed with the experiment and did want to help her, but he lost this when he uploaded to the net and became completely obsessed with the experiment.
Graceful Loser: When faced with a digital missile to the face, he starts out saying that there will be more of him eventually. Kai just tells him that even so, those who fight back will still win. He accepts this and goes out with a smile.
Pet the Dog: His short time with Airi may or may not be this. The flashback scene at one episode as well as Airi's words in episode 21 implied that his treatment on her was genuine, but his words in the previous episode also implied that she was merely a test subject for his consciousness-uploading experiment.