Lupin III came to Japan for the phantom treasure, Cherry Sapphire. At the same time, Conan escorts the popular idol Emilio, who is visiting Japan, with Kogoro. When the two cases collide, the beliefs of a great thief and a detective clash!!

Conan and Kogoro head to the Kingdom of Vespania to save Ran, who was involved in the princess' disappearance. However, Lupin and his friends infiltrate Vespania, going after the royal family's treasure! With the detective's and the thief's paths crossing, how will this end!?