Mori Kogoro's private investigation office receives a blackmail call one day, but the caller dials the wrong number. Conan recognizes the voice as similar to that of his old pal Heiji, a fellow high school detective from Osaka. Together, they team up to crack the case and recover the stolen jewel. However, they're not the only ones on the hunt for the prize. Kaitou Kid, a notorious master thief with a keen eye for valuable treasures, is also eager to acquire the jewel, which boasts a value of 100,000,000 Yen. It's now up to Heiji and Conan to outsmart the competition and apprehend the culprit while securing the coveted gem.