A warning arrives from Kid, the Phantom Thief, claiming he will pilfer a Japanese sword owned by the affluent Onoe clan in Hakodate, Hokkaido. Conan and Heiji Hattori, who happen to be in Hakodate, take up the task of apprehending Kid. The Onoe collection is tied to Toshizo Hijikata, a historical figure who died in Hakodate, and his legacy looms large. Why would Kid, known for jewel thefts, target a Japanese sword?
Simultaneously, the Onoe family"s attorney is discovered dead in the warehouse district, apparently slain by a Japanese sword. The prime suspect is an investor‑arms dealer rumored to pursue the Onoe family"s concealed treasure.
The grandfather of the current Onoe patriarch was deeply involved in wartime armaments, and whispers claim he hid a powerful weapon capable of "altering the course of war" somewhere in Hakodate. Is Kid after that relic? Meanwhile, Heiji seeks the perfect spot to profess his love to Kazuha…
In the northern region beneath blooming cherry trees, the thrilling treasure hunt commences and the stakes rise.
