The mystery unfolds inside a concert hall where every note matters, where a Stradivarius violin and perfect pitch become weapons in a killer's hands. Classical music isn't decoration here, it's the language of the crime itself, which means you're solving the puzzle alongside Conan instead of just watching him solve it. Akiba Reiko doesn't feel like a sidekick dropped into the case; she belongs there, and that changes how the investigation breathes. If you've watched enough Detective Conan to know the formula, this one breaks it by making the music the actual suspect.

A string of serial murders has claimed victims who all come from the same music school, one run by a famous pianist. That same pianist has built a new music hall, and Conan and his companions receive invitations to its opening concert. The evening's biggest draws are a world-famous Stradivarius violin and a guest appearance by a singer with perfect pitch. This feature-length Case Closed film blends mystery with music, placing Conan at the concert while the killings connected to the school remain unsolved.