The Kaitou Kid - aka Kaito Kuroba - is currently on the prowl for his next heist: the Crystal Mother, Europe's largest Topaz! However, acquiring the jewel won't be easy as it has been hidden by its owner, the Queen of Ingram, aboard the Royal Express luxury train. What's worse is that not only Conan, but also the crown prince of Ingram stand in his way! Will Kaitou Kid pull off the crime of the century?
After robbing a casino and finding out the entire take was counterfeit, Lupin and Jigen are off to the duchy of Cagliostro to find the source of this trickery, and to stop it. Upon arrival, the two become entangled in a car chase between a woman in a wedding dress and several men in a black car. Before she is kidnapped, this woman passes off a ring to Lupin, a ring that sparks his interest more than counterfeit money ever could. Unfortunately for Lupin it also grabs the attention of those who want the ring back, and would kill him for it in a heartbeat.
Like Conan OVA 6, Castle of Cagliostro is a thief's tale with a campy edge. If you enjoyed watching Kaitou Kid try to get his hands on the diamond in Conan OVA 6, you'll appreciate Lupin's adventures in Castle of Cagliostro.