Juuga, a figure from the ancient Kaiju Eugenicists, once aided a kingdom’s golden age 5,000 years ago by harnessing kaiju under the leadership of Gauma, whom he revered. Alongside allies Onija, Mujina, and Sizumu, he pursued prosperity until betrayal by the very rulers they served fractured the group. Gauma’s subsequent turn against them culminated in their deaths.

Resurrected in the modern era, Juuga’s demeanor remains unflappable, a counterbalance to his more impulsive companions. His glasses, worn to correct age-weakened vision, underscore his methodical nature. Preferring dialogue over conflict, he frequently adopts diplomacy when confronting opponents, leveraging his rationality to steer the group’s strategies.

Convinced that Yomogi Asanaka and his peers—capable of piloting Dynazenon—held latent potential as Kaiju Users, Juuga sought to recruit them. He infiltrated Yomogi’s school and probed Gauma’s motives, seeking clarity on their leader’s past defection. Though loyal to the Eugenicists’ goals, Juuga later attempted reconciliation with Gauma, only to face violent rejection.

His signature ability, Instance Domination, enables precise control and enlargement of kaiju while dissecting their traits. He wielded this power over Greyjhom and Gibzorg, then collaborated with allies to command Gagula’s evolved form. In their final stand, the Eugenicists fused with Gagula to amplify its might, but perished alongside the creature in battle.

Visually modeled after musician Masayoshi Oishi, Juuga’s name derives from the Chinese adage “駑馬十駕,” reflecting tenacity triumphing over limitation. His calm facade masked unresolved tensions with Gauma and quiet doubts about their mission—nuances lingering beneath the surface until his abrupt end.