A 6th grader who possesses the Metal Breath, a device used to summon and operate with Metal Cardbots. It recognizes Metal Cards to materialize the bots, serving as a vital link between humans and machines. He uses the Metal Breath to start battles and utilize the bots' powers. Jun is bright, energetic, and has a strong sense of justice, never ignoring someone in trouble. He is curious and proactive, often stepping forward first in dangerous situations because he values his friends and allies so much. He possesses the persistence to never give up. He speaks naturally and comfortably like a typical boy his age, using casual speech and joking with friends, but becomes calm and firm in serious or dangerous moments. He treats Metal Cardbots as trusted partners rather than just giving them orders.

A police car Metal Cardbot who is always the first to step forward in a crisis. As a Star Guardian, he uses a calm and composed tone, prioritizing reason over emotion and speaking only when necessary. During battle, his speech is firm and powerful, showing deep trust and respect for Jun. He has a strong sense of responsibility and justice, a spirit of self-sacrifice, and absolute faith in his allies. He has a great desire to protect people, though he often shows an eccentric side. While generally bright, he is dead serious during missions. He possesses high mobility, excellent judgment, and situational response skills, specializing in rescue and pursuit. He excels in close combat, marksmanship, defense, and protecting allies, showing great leadership in guiding the team.

A large truck Metal Cardbot characterized by immense strength and superior defense. He is reliable and fiercely loyal, always thinking of his allies first. Using a giant hammer, he delivers powerful melee attacks and serves as the team's dependable shield.

An ambulance Metal Cardbot responsible for saving people and healing allies. He is gentle and considerate, valuing life and safety over fighting. His tone is calm and soft, always speaking in a way that worries for and reassures others.

A fire truck Metal Cardbot with powerful combat abilities using flames. He is passionate and has a strong sense of justice. Interestingly, he is a bit afraid of fire, which makes him hot-blooded and unable to tolerate injustice. However, he values his allies and is highly responsible. His tone is confident and energetic, expressing his emotions honestly. In battle, he uses a hot and spirited way of speaking.

A small plane Metal Cardbot specializing in high mobility and aerial combat using his small frame. He is playful and mischievous, fearlessly facing opponents much larger than himself. His tone is light and joking, often teasing others or making wisecracks. However, in combat situations, he shows a serious side with quick decision-making. He is the shortest among the bots.

A pirate ship Metal Cardbot and the captain of the Black Gang. In ship form, he floats in the air. He is charismatic, confident, and loyal to his crew, though he occasionally shows a clumsy or eccentric side. He speaks with the boisterous and dignified tone of a sea captain, leading Buffalo Crush and Buster Gallon with great strength and leadership. He stands about 10 meters tall when transformed. He has a poor relationship with Heavy Iron and is constantly at war with him. He has not been sealed yet.

A monster truck Metal Cardbot who is a subordinate and ally of Black Hook. He calls Black Hook "Captain." While he is extremely strong and rough, he is loyal and follows Black Hook faithfully. His speech is coarse and simple, often sounding a bit dim-witted but boisterous, showing off his strength and confidence. He frequently eats electricity because he is hungry. He has not been sealed yet.

A tank Metal Cardbot who is an ally and subordinate of Black Hook. While he possesses strong combat power, his main trait is his talent as an inventor who creates new machines and devices. He is curious, sly, and takes great pride in his inventions. He has a unique way of speaking, using polite honorifics with everyone while maintaining a relaxed and oily atmosphere. He has not been sealed yet.

A container truck Metal Cardbot. When transformed, he is a top-tier outlaw standing at a massive 18 meters with the greatest strength among all Metal Cardbots. He is a dangerous entity who ignores rules and order, acting as he pleases through overwhelming brute force and destructive power. He is serious, cynical, and possesses high self-esteem, hating to be ignored. His voice is low, heavy, and cold, creating an atmosphere that pressures his opponents. He frequently wages war against Black Hook. He has not been sealed yet.