Meitantei Conan

Three months before high school sleuth Kudo Shinichi is made to drink poison by a mysterious organisation and becomes Edogawa Conan, he receives a succession of written challenges giving him notice of murders. Using his brilliant deductive ability, he untangles affairs and loves to solve the riddle of the impossible murders.
~~ Adapted from the manga "Detective Conan" (名探偵コナン) by Aoyama Gosho (青山剛昌).