A robbery goes wrong when a gang starts to murder it's victims. One gang member manages to escape, but is shot with a crossbow bolt in the process. While Conan and the Detective Boys are on a weekend adventure with Professor Agasa, they find the shot gang member passed out on a villa property. It seems the gang is still hunting for him.

The Detective Boys go to Gifu to explore and see a local hero show. Afterwards, Mitsuhiko goes to ask for their autographs. While waiting, the Detective Boys feel he's been gone a long time. When they go to their tent, they find the heroes and Mitsuhiko have gone missing!