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.

When a little boy is caught in a devastating fire, the Junior Detective League is on the case! Conan suspects arson, but to decipher the clues his pint-size client left behind he'll have to think like a real first grader!

Then Conan tracks the Hammer Man, an urban legend who leaves all-too-real victims. And Richard Moore is prepping for his latest TV appearance when he stumbles upon a death by poisoned coffee. Can Conan brew up a solution to the caffeinated crime?