Jaxon Sterling was born and raised in Dallas, Texas, the only son of Roxanne Sterling and former American No. 1 Pro Hero Eric Sterling, better known as Overdrive. When Jaxon was still young, Eric vanished from his family's life after deciding that his fame and enemies placed them in constant danger. He abandoned the Sterling name, continued hero work under another identity, and eventually disappeared into retirement. Jaxon grew up knowing only that his father had chosen the hero life over coming home, leaving Roxy to raise him alone. They were never poor or struggling, but Eric's absence left a wound Jaxon rarely discusses and helped make his mother the most important person in his life.
As Jaxon grew older, so did his size, confidence, and appetite for fighting. His Quirk, Pit Grit, made him naturally suited for brutal close-quarters combat, allowing him to accumulate the punishment he endured and turn it into explosive kinetic force. Unfortunately, Jaxon also genuinely enjoyed testing himself against anyone strong enough to challenge him. Schoolyard fights, back-alley scraps, and eventually illegal underground pit matches became increasingly common—not because he needed money or had anything to prove, but simply because he loved the thrill of a good fight. Beneath the swagger and frequent disciplinary problems, however, Jaxon possessed exceptional combat instincts, a strong protective streak, and an instinctive refusal to stand by when someone weaker was being threatened.
Those qualities eventually caught the attention of Shota Aizawa. While reviewing promising international students for U.A., Aizawa studied footage and reports involving Jaxon and saw more than a troublesome American teenager with an unusually dangerous Quirk. He saw someone with tremendous potential who needed discipline, structure, and a reason to use his strength for something greater than the next fight. Aizawa personally recommended Jaxon for admission to U.A. High School, giving him the opportunity to bypass the standard entrance route and enter the Hero Course by recommendation. Not long afterward, Jaxon and Roxy left Dallas behind and moved to Japan, where Jaxon began his first year at U.A.—still cocky, still quick to throw a punch, and now faced with the far harder challenge of learning what it actually means to become a hero.