Height: 160cm Gender: Male Species: Human (Earthling) Personality: Altruistic and kind-hearted. He has a generous spirit, immediately helping anyone in danger even if they are a stranger. He treats the Metal Cardbots as friends rather than subordinates. Characteristics: He becomes the owner of the Metal Breath he found by chance, sealing, healing, and befriending Metal Cardbots. He forms a deep bond with BlueCop, a police car-type Metal Cardbot, as they solve various incidents. He has a crush on Anna. He has blue hair.

Height: 160cm Gender: Female Species: Human (Earthling) Personality: Kind and gentle, but she struggles to speak up confidently or take the lead. She is a poor liar. Characteristics: She attends the same school as Jun and is his very close friend. She has pink bobbed hair, green eyes, and usually wears skirts. She is very pretty.

Robot Mode Height: 5.5m Gender: Male Species: Metal Cardbot Vehicle Mode: Police Car Personality: Just, cautious, and deeply affectionate. He is fiercely protective of Jun, though he can be eccentric at times as he struggles to adapt to Earth culture. Characteristics: He views the Metal Breath as a symbol of friendship and cannot stand to see Jun in danger. He was a Star Guardian (equivalent to a police officer) on Planet Machina. He is currently sealed by Jun. His weapon card is the Justice Gauntlet.

Robot Mode Height: 5.4m Gender: Male Species: Metal Cardbot Vehicle Mode: Ambulance Personality: Cautious and blunt. He isn't easily swayed by emotions, but he is a skilled healer with a tsundere personality. Characteristics: He views the Metal Breath as a symbol of friendship and is fiercely protective of Jun. He was a medical officer in the 13th Unit of the Star Guardians on Planet Machina. He is currently sealed by Jun. His weapon cards include Mega Forceps, Forceps Shock, and Forceps Crush.

Robot Mode Height: 5m Gender: Male Species: Metal Cardbot Vehicle Mode: Truck Personality: Despite his massive and reliable appearance, he is deep-hearted and optimistic. He is always positive, loves to dance, and carries himself with confidence. Characteristics: He views the Metal Breath as a symbol of friendship and is fiercely protective of Jun. He is currently sealed by Jun. His weapon cards are Mega Power Shield and Mega Power Tackle.

Robot Mode Height: 5.9m Gender: Male Species: Metal Cardbot Vehicle Mode: Ladder Fire Truck Personality: Usually timid and honest, but at fire scenes or in emergencies, he becomes braver than anyone, diving in with bold sincerity to extinguish flames. Characteristics: He was a firefighter on Planet Machina. His weapon cards are Aqua Cannon and Fire Hammer. He suffers from fire-related trauma due to a fire that broke out while he was traveling to Earth in an escape pod. Consequently, he immediately douses even the slightest hint of heat or fire with water.