In a world inspired by ancient Rome, becoming a gladiator is the fastest path to wealth, fame, and freedom. Lux, a gentle slave boy, endures his chained life because he has two precious friends: Ven, who dreams of freedom through the arena, and Freeche, who quietly adores Lux. Their simple happiness is shattered when Freeche is killed after offending a noble, and Ven is executed for speaking out. Grief-stricken and furious, Lux chooses the sword over the chain. He vows to become a gladiator and reclaim the freedom that was stolen from his friends.

Lux's path crosses with a drunken old man who turns out to be the legendary gladiator Achilles, a name that once shook the arena. Under Achilles' harsh training, Lux hones his natural talent keen eyesight and reflexes that let him read opponents' moves. He gathers a team of misfits: Luna, a battle-crazed warrior, and Beem, a gentle giant with surprising skills. Together they form the Bao Gladiator Troupe and enter the brutal arena, where they face everything from corrupt judges to the "Citizen Killer" Rayblood, a notorious criminal who evokes Lux's sympathy despite his crimes.

The story takes an abrupt leap forward several years, focusing on the final, climactic battle between Lux's troupe and their rivals. Lux's ultimate wish to protect and free those he cares about is put to the test in a savage showdown. Though the narrative was cut short, it closes on a note of sacrifice and resolve, with Lux facing his last fight as the champion he swore to become.