Sergio Caldone serves as Chief of the Italian police force, operating within Italy as its high-ranking law enforcement authority. He oversees the high-stakes kidnapping investigation of prominent Italian CEO Rebecca Rossellini, a case falling directly under his jurisdiction. This investigation draws multiple figures into his operational sphere: Lupin III arrives in Italy to respond to the kidnapping and a challenge from the mysterious Masked Count; Inspector Zenigata enters the country in pursuit of Lupin; and British MI-6 Agent Nyx independently tracks the Masked Count. Caldone coordinates police efforts concerning Rossellini's abduction and the associated criminal activities tied to the Masked Count's contest to locate the Count of Cagliostro's inheritance. The paths of Caldone, Lupin, Zenigata, and Nyx converge during these events. His documented role is confined to this professional capacity within this operation.