Burdened by debt after a coworker defaults on a loan, aimless drifter Kaiji Itou is cornered by loan sharks with no way out. Desperate and broke, he accepts a risky invitation aboard the luxury ship Espoir, where a single night of gambling promises enough money to erase his debts. But what begins as a simple gamble soon turns into a brutal battle of deception, strategy, and survival. Surrounded by desperate players and crushing stakes, Kaiji must outthink his opponents and make impossible choices as each wager pushes him closer to ruin or escape.