Set against the glittering backdrop of Marina Bay Sands in Singapore, the film revolves around the legend of the "Blue Sapphire," a colossal, flawless gemstone said to have sunk to the ocean floor aboard a pirate ship in the late 19th century. Millionaire Lee Leonard seeks to claim the jewel for an exhibition, inadvertently setting off a labyrinthine conspiracy involving murder, theft, and
corporate greed.The chaos begins when a local attorney is brutally murdered at the iconic Marina Bay Sands hotel, leaving behind a blood-stained karate champion’s belt belonging to Makoto Kyogoku. Meanwhile, Conan Edogawa is forcibly—and quite illegally—smuggled into Singapore inside a locked travel trunk by the master thief Kaito Kid, who needs Conan’s brilliant deductive mind to solve a locked-room murder and crack the security systems guarding the Blue Sapphire. Kid disguises Conan under the alias "Arthur Hirai," forcing the shrunken detective to navigate the perilous underworld alongside his childhood friend, Ran Mouri, and karate master Makoto, who are visiting Singapore for a
martial arts tournament.As the tournament progresses, dark forces mobilize. A ruthless faction of pirates, led by a scarred mastermind, orchestrates a violent attack on Singapore, kidnapping Ran’s fierce rival, Sonoko Suzuki, to use as leverage against Makoto. The pirates' ultimate goal is not just ransom, but to hijack Lee Leonard’s high-tech cargo ship, turning the vessel into a floating weapon to destroy the city’s financial district and seize the Blue Sapphire for themselves.Conan, using his signature high-tech gadgets, races against the clock to dismantle the pirate syndicate. Alongside Kaito Kid, who harbors his own mysterious agenda regarding the sapphire's true ownership, Conan uncovers a web of betrayal linking Lee Leonard’s closest associates to the piracy ring. Tension peaks when Makoto unleashes his devastating martial arts prowess to rescue Sonoko, destroying a small army of mercenaries with sheer physical dominance. Simultaneously, Conan confronts the mastermind aboard the hijacked cargo ship, utilizing a combination of physics, precise gadgets, and Kaito Kid’s illusionary mastery to neutralize the threat.In the chaotic climax, the Blue Sapphire is secured, the villains are arrested, and Singapore is saved from catastrophic destruction. As the dust settles, Conan manages to outsmart Kaito Kid once again, though the elusive thief makes a daring escape into the Singaporean night. Ultimately, the relationships among the core characters are tested and strengthened, leaving the heroes to return to Tokyo, forever changed by their tropical adventure.