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.

A judge is stabbed at a kendo tournament where Harley is competing--and preparing to confess his feelings to Kazuha. A waiter is brutally murdered at a café, and every one of his coworkers has a motive. As the Detective League heads home from a soccer match, a crook is strangely fixated on stealing Anita's beloved souvenir. Conan can handle all these cases and more, but they're nothing compared to the bigger problem consuming his every waking moment: Can he turn back into Jimmy Kudo just long enough to join Rachel on a romantic class trip to Kyoto?