In the early 70's, gory films were nothing new in Japanese cinema as several years earlier, infamous director Teruo Ishii had already introduced new heights of violence in his TOKUGAWA series for Toei Studios.
What was new was the combination of bloodshed and aesthetic cinematography, which made the LONE WOLF AND CUB films stand out. It did for swordfighting films what Sam Peckinpah's THE WILD BUNCH had done for the Western genre several years earlier.
Responsible for four of the six films in the series was veteran director Kenji Misumi. Misumi was already well known for directing the very first of the highly-successful and long-running ZATOICHI movies (starring Shintaro Katsu, who also produced the LONE WOLF AND CUB series and was the brother of the main actor) as well as the second and best of the three DAIMAJIN films.