the story is set at the beginning of the 18th century in feudal Japan.Having become embroiled in a feud in his home domain, a young swordsman named Matahachiro leaves for the city of Edo (now Tokyo). There he embarks on a new and eventful career as a yojin-bo, or bodyguard. Matahachiro happened to hear about a conspiracy for the assassination of his lord, and his fiancee's father was part of the plot. Matahachiro was forced to kill him in self-defense. In Edo, an embittered Matahachiro works with his counterpart Gendayu Hosoya. As he faces various incidents, he even crosses paths with the famous "47 ronin", a group of samurai who are plotting to revenge the death of their master, the Lord of Ako.