Big Bang commands the villainous Big Bang Organization, an egocentric team bearing his chosen name. His true identity is Taiki Amanogawa, father to protagonist Ryūsei Amanogawa and the long-lost older brother, Ginga Amanogawa. This familial bond casts him as an Archnemesis Dad to both sons.

His past is marked by abusive parenting, especially towards Ginga. He inflicted intense "Training from Hell" during Ginga's childhood, forcing heavy labor, endurance under waterfalls, and nocturnal borg machine practice. This abuse drove Ginga to flee Japan for Germany at age four. His ambition for world domination crystallized at Ryūsei's birth, forming a plan to seize control.

Physically, as Big Bang, he adopts a distinctive look: consistently shirtless, wearing only a mask, cape, and pants. His methods are extreme, including disguising himself as a girl to falsely accuse Ryūsei of stalking, then inciting an angry mob to stone his own son. He shows willingness to harm children, evident in his treatment of Ryūsei and his approval of an assassination attempt against Ryūsei via blowgun in episode 30.

Despite his abusive nature, he occasionally displays genuine pride in his sons' growth, revealing a complex relationship. He leads subordinates like Gulfstream Sasamoto and Ogawa Shangrila within the Big Bang Organization. The organization antagonizes by destroying children's Kabutoborgs, contrasting the protagonists' own questionable actions.

The Amanogawa family follows cosmic naming motifs; "Amanogawa" translates to "Milky Way." This theme extends to his alias, "Big Bang." His dual identity as Taiki Amanogawa is abruptly revealed in the first episode's twist ending, establishing his role as father and nemesis early on.