The Detective Boys/Junior Detective League are given a project by their teacher to study a person in their line of work. They decide to study Kogoro/Richard as he perform his duties as a private detective. They secretly follow Richard as he investigates Masaya Murakami, the boyfriend of a daughter of a rich family. Masaya is later kidnapped by a gang due to having a friend borrow money from them. Conan finds it strange they kidnapped Masaya for the money and realizes they intend to blackmail Etsuke Yamo, Masaya's girlfriend, to pay for Masaya's life...