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! When ace high school detective Jimmy Kudo is fed a mysterious substance by a pair of nefarious men in black--poof! He is physically tranformed into a first grader. Until Jimmy can find a cure for his miniature malady, he takes on the pseudonym Conan Edogawa and continues to solve all the cases that come his way.