Bucky, son of King Bucky the Twelfth Great Child of Doedicos, witnessed an attack by Slash during his childhood. His father fought while young Bucky and the entire island were frozen. Later freed from the ice but with erased memories, he was teleported to Primas, the first world.

Initially cold and anti-social, Bucky treated college friends like slaves despite possessing a good heart and caring for those close to him. His ambition to conquer the world and become the best Great Child led Spaak, Primas's Great Child, to choose him as successor after seeing his courage and determination in saving friends from a Trouble Monster. Bucky then journeyed across the twelve worlds with his spirit companion Jibac and friends Pinky and Kai.

Throughout his travels, Bucky aided individuals across worlds. In Tetras, he helped Dartagnan confront fears and defeat a monster possessed by his father's spirit. In Pentas, he aided Ali Babah in breaking a curse that revealed her true identity. He mediated conflicts between manipulated siblings Live and Dead in Hexas and Novas, caused by their recurring adversary Hail. He supported Runmaru in Seteras against the Toad Lord, though Master Funen ultimately defeated the transformed monster. In Octas, he devised a plan to help Lucy reclaim her father's ship from the Balboa Gang.

Bucky's abilities evolved significantly. He demonstrated high durability, like withstanding Live's Soundwave Trap. In Dicas, after injury and encountering Hayate, he gained the power of the Great Soldier, emitting white light to protect Hayate from a Holy Tree corrupted by Slash's Poison of Awakening. Later, in Undicos, he learned the Purifier technique from Busta (Master Funen in disguise), using it to cleanse individuals and monsters afflicted by Slash's corruption, including Ash and Joan's drive monster Doberg.

Reaching Doedicos, Bucky encountered King Jibac, his father's spirit, who revealed his heritage and childhood freezing. King Jibac urged Bucky to replace his frozen father as Great Child, but Bucky refused, prioritizing his dream of ruling the world. He showed minimal respect, kicking the ice that once held him before proceeding to Needle Tower.

At Needle Tower, Bucky confronted Slash possessing the Princess. With Spaak's assistance, Slash was temporarily defeated and expelled. Bucky ultimately destroyed Slash's dragon form using the Princess' sword combined with twelve spirits' power. Following this victory, reunited with fellow Great Children, Bucky realized his world conquest dream could not be realized as envisioned. The license and watch from Spaak were revealed as part of a dream, yet his deeper aspiration for fulfillment was achieved.

Bucky's personality shifted from cold and domineering to compassionate and protective. He polished Jibac while conversing with allies like Hayate and intervened to prevent Joan from killing her corrupted drive monster. His appearance featured long spiky black hair with brown highlights. He typically wore a red short-sleeved leather jacket, pale yellow shirt, light purple shorts, and white gloves, occasionally adopting traditional Japanese attire in Seteras and a military suit with a wig in Undicos.