Samurai Executioner

the story is set in the edo period of feudal japan. it revolves around yamada asaemon, nicknamed kubikiri asa (literally “neck-chopper asa”, often transliterated as “decapitator asaemon”), a ronin who is responsible for testing new swords for the shogun. the character is based on a real-life line of sword-testers who served the tokugawa shogunate up to the early 19th century. — wikipedia