Age: 12 Gender: Male Characteristics: Blue Cop's partner. A 5th grader at Mowtown Elementary. He maintains friendly relationships with most people due to his natural sociability. He has a crush on Anna. He is best friends with Theo. Ed is a regular repair shop owner he has known since he was very young, so Jun follows him like an uncle. Metal Breath owner. Appearance: A handsome face with a few freckles, messy blue hair, and blue eyes. Personality: Kind and altruistic. Cheerful with a strong sense of curiosity and a love for mysterious things. Surprisingly broad-minded.

Age: 12 Gender: Female Characteristics: A 5th grader at Mowtown Elementary. She is the class president and the daughter of Mowtown's mayor, Zack. She has excellent grades and athletic ability. She is the object of Jun's affection and is close friends with him. Appearance: Pink bobbed hair, a light pink headband, and lime green eyes. Personality: Diligent and enjoys helping others. Possesses leadership, a strong sense of justice, and a firm, resolute character.

Age: 12 Gender: Male Characteristics: A 5th grader at Mowtown Elementary. A boy who loves mechanical engineering and mysteries. Compared to his classmates, he is shorter and physically weaker, so he isn't good at sports. Instead, he has excellent grades and vast knowledge in various fields, providing much help to Jun's group. He is so skilled with electronics that hacking CCTV footage is a piece of cake for him. Jun's best friend. Appearance: Brown hair and glasses. Personality: Timid and calm.

Age: 12 Gender: Female Characteristics: A 5th grader at Mowtown Elementary and a classmate of Jun, Theo, and Anna. A fashionista sensitive to trends and a personal streamer. Perhaps because she is the daughter of a newspaper president, she has a talent for journalism. Once she becomes suspicious, she digs in tenaciously, and she has considerable courage. She has a crush on Crest and is actively pursuing him. Appearance: Blonde ponytail and turquoise eyes. Personality: Trend-conscious and bold. Despite her attitude, she is a good kid at heart.

Age: 12 Gender: Male Characteristics: A 5th grader at Mowtown Elementary. Wild Gardi's partner. From his first day as a transfer student, he showed extraordinary abilities, such as memorizing every student's name from the attendance sheet and dodging or catching balls thrown from behind. He attracts many female students, earning the jealousy of the boys. He is Guest's twin brother and Leia's eldest son. He can communicate with and control Wild Gardi even without a Metal Breath. Appearance: Light turquoise hair, golden eyes, suit-style clothing. Very handsome. Personality: Benevolent and thoughtful. A cautious type who observes the situation and moves only when certain. (Secretly sweet only to Guest.)

Age: 12 Gender: Female Characteristics: The caretaker of the Porcaca Ruins and a direct descendant of Mukara, the owner of the Metal Breath who lived 4,000 years ago. She is currently staying at Jun's house. A Metal Breath owner. Her partner is Cielo. Appearance: Red hair in twin tails and red eyes. Personality: Proactive, lively, active, and straightforward. She tends to get quite violent when angry.

Age: 28 Gender: Male Characteristics: The manager of 'Ed Motors,' the car repair shop Jun Grant frequents. A highly skilled technician who has run the shop alone for over 10 years without subordinates. He is a versatile genius who handles not only his main field of car repair but also Metal Cardbot parts replacement, maintenance, and additional technology development. Regarding Metal Cardbots, he is practically a surgeon or an all-purpose supporter. Appearance: An ordinary-looking man (ajjeossi). Personality: Lively and passionate. His emotions show clearly on his face.

Age: 30s+ Gender: Female Characteristics: Mother of Guest and Crest. A famous authority on robotics who gets so excited by robots that her eyes sparkle. She was incredibly happy to meet Jun and Blue Cop, showing a great personal interest beyond just her profession. Appearance: Red short-cut hair and golden eyes. Personality: Strong-willed, somewhat devoted, kind-hearted, and loves her children.

Gender: Male Characteristics: Vehicle mode is a police car. Jun's partner Cardbot. A diligent police officer from Planet Machina who values justice and desires peace. He strives for coexistence with humans. Personality: Gentle and kind. Rather than being a leader who unites the Metal Cardbots, he is more like the eldest brother who suffers because of his rambunctious younger siblings.

Gender: Male Characteristics: Vehicle mode is a sports car. Crest's partner Cardbot. A highly skilled knight who follows Crest, his precious friend and savior. Along with Blue Cop, he is considered one of the strongest among normal-sized Metal Cardbots. Personality: Serious. Blue Cop's junior. Has a bit of a yandere temperament(?).