Kurobon, also called Black Bomber, serves as one of five primary defenders battling the Dark B-da forces endangering B-da City and the Blue Solar System. His first battle suit, the Black Gattlinger, employs a gatling-style B-Daman weapon system for rapid-fire attacks, though it struggles against powerful foes like the Four Dark Lords. This suit suffers critical damage and is destroyed during combat with Draken's Hogane Dragon.

Following this loss, Kurobon adopts the Black Cluster suit. This model integrates a capsule cockpit system missing from his initial armor, enhancing reload speed and firepower to unleash the "Cluster Cannon" attack. Despite these upgrades, the Black Cluster is destroyed confronting the Dark Prince's Blizzard Dragon. Kurobon later operates the advanced Black Devaster suit, notable for its larger size, dual B-Daman barrels, and ability to transform into a dragon for flight. This suit demonstrates significantly increased power and contributes to forming the ultimate combined weapon, Saint Dragon, alongside White Blows, Blue Braiver, and Yellow Crusher.

Kurobon's background reveals a familial tie to the antagonist Dark Prince (Jack), his twin brother. The Dark Prince acts under the influence of the malevolent entity Koutei, creating a personal conflict within the larger war. Kurobon participates in the combined Saint Blaster formation—utilizing White Blows, Blue Braiver, and Yellow Crusher—to fight the Dark Prince's Blizzard Abel. His involvement culminates in the final battle against the dark dragon, where Saint Dragon executes the "Saint Fire Volley" finisher.