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.

The Kaito Kid is infamous for his heists, but this time the master thief wants to return something: a collection stolen historical artifacts. The authorities plan to use the opportunity to nab the Kid at last, but Conan suspects his nemesis has something up his tailored sleeve...

Then Conan and Harley get the chance to debunk a deadly host story. But the fiery spectral hound haunting a family won't be snuffed out so easily!