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 legendary samurai Toyotomi Hideyoshi has just died a second time: a historical re-enactor playing Hideyoshi has been killed at the daimyo's own Osaka Castle. Time for Conan to make history stop repeating itself--and for Osaka native Harley Hartwell to pick up a wooden sword and eke out some old-fashioned justice!

Then Detective Moore attends a star-studded engagement party on the arm of idol singer Yoko Okino...but the festivities are cut short when one of the stars of Yoko's old girl group is attacked in the bath!