Monkey D. Luffy and his Straw Hat Crew embark on Gran Tesoro, a colossal floating entertainment hub. Seduced by the allure of riches, they venture into the grand casino and ride a wave of inexplicable fortune. The crew accepts a risky challenge from Gild Tesoro, the city's enigmatic ruler, placing their trust in Luffy's legendary luck. But as they fall prey to a treacherous scheme, they uncover the city's sinister underbelly. Bereft of their winnings, the Straw Hat Crew must gamble on a daring scheme with the aid of newfound allies to reclaim their lost treasures before their fortune dwindles to nothing.