Path of the Assassin is the story of Hattori Hanzou, the fabled master ninja whose duty was to protect Tokugawa Ieyasu, who would grow up to become shogun and unify Japan. The creators poetically describe the story as "lifelong friends, with the same dreams, striving to grow into a rising river."

Hanzou no Mon was published in English as Path of the Assassin by Dark Horse Comics from July 11, 2006 to May 12, 2009 and in Spanish by ECC Cómics in 10 volumes from October 1, 2014 to March 30, 2016.