Jimmy Kudo, the son of a world-renowned mystery writer, is a high school detective who has cracked the most baffling of cases. One day while on a date with his childhood friend Rachel Moore, Jimmy observes a pair of men in black involved in some shady business. The men capture Jimmy and give him a poisonous substance to rub out their witness. But instead of killing him, it turns him into a little kid! Jimmy takes on the pseudonym Conan Edogawa and continues to solve all the difficult cases that come his way. All the while, he's looking for the men in black and the mysterious organization they're with in order to find a cure for his miniature malady.

Detective Moore investigates a wealthy family whose members share a gift for music--and a habit of dying under mysterious circumstances. When a deadly fire sweeps through the estate, Conan suspects that the killer has struck again. With the help of a priceless violin, can he sound the note to solve the case?

Meanwhile, Conan has finally found a clue to the whereabouts of the elusive Men in Black. But if he hits the wrong note, it'll be time to play his requiem...