Lupin III vs Detective Conan (ルパン三世VS名探偵コナン) is a crossover work of Lupin III and Detective Conan (aka Case Closed): Something is rotten in the Kingdom of Vespania. Queen Sakura and her son Prince Gill have died in a suspicious hunting accident. Such shocking tragedy become widespread on the news around the world. Of course, it even couldn't escape from the ears of Arsène Lupin III and Conan Edogawa either. The death of Queen Sakura and Prince Gill means that her first daughter, Princess Mira, is next to take the throne, but she refuses to do so since she hears the tragic news. Meanwhile, during Princess Mira's visit in Sakura Saku Hotel in Japan, Conan Edogawa and Ran Mouri get involved in an intriguing incident. Conan Edogawa discovers that someone is after Princess Mira and tries to poison her. Also, when Princess Mira tries to escape from her bodyguard, she runs into Ran Mouri, who so coincidentally resembles her. Mira wants to be free for one day, and Ran wants to become a princ