Can Detective Conan crack the case...while trapped in a kid's body? 
When ace high school detective Jimmy Kudo is fed a mysterious substance by a pair of nefarious men in black--poof! He is physically transformed 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. 
When an heiress drowns in a hotel pool, Conan and Sera are on the scene to dredge up the truth. Then a screenwriter is found dead in a scenario straight out of one of her mystery scripts. And Conan and Harley investigate a mythical beast that seems to be committing very real murders. 
Meanwhile, Conan tries to learn something--anything--about Rum, the high-ranking Man in Black who's as secretive as he is dangerous. There's also the question of the strange little girl monitoring Conan and his friends from a distance. With these mysteries lurking in the shadows, how can Conan keep his mind on his cases?