Midoribon, alias Green Bomber, features in two franchise storylines. Initially, he commanded the rebel guerrilla force on Jupiter during the conflict against the Nol Arc Empire and Emperor Dark Bomber. Exhibiting a serious personality, he wore a green beret and piloted a Lumber Bomber Fighter aircraft. Though initially under Imperial sway, receiving Jupiter's Planet Emblem power transformed his B-Daman, enabling him to guide Shirobon and allies.

Later, within the Borderland Kingdom narrative, Midoribon held the rank of sergeant and led the Borderland Knights. Following Crismond's death, a space-time rift catapulted him and his tank, the Grand Greaver, to Robinson's Crewe Island. He initially mistook Shirobon's group for enemies but reconciled upon recognizing Akabon. His fierce dedication to the kingdom and Princess Red Bomber fueled extreme loyalty, frequently triggering a "Gyokusai Mode" where he pursued martyrdom.

His personality blends bravery, passion, and seriousness, often manifesting as a lack of composure and emotional outbursts. He experiences jealousy towards Kurobon when outperformed in resolving crises. A significant flaw is his poor sense of direction, notably causing critical misnavigation within B-Da Sargasso's radar-disabling fog. Key relationships define him: he shares a strong bond with the young witch Witchy, treating her as a sister figure despite her potential crush, while his devotion to Red Bomber borders on the extreme.

Midoribon pilots specific B-Da Armors: the Grand Greaver, capable of the "Double Metal Shot" attack, and later the Crys Greaver, wielding "Super Metal Double Shot." His armor contributes to forming the legendary combined entity, B-Da Calibur. Demonstrating pragmatism after the Borderland conflict, he recruited the rehabilitated Devil Three Musketeers into the Borderland Knights. Physical changes occurred when wearing Chris Greaver's mail suit, turning his body a yellow-green color.