Samurai Justice: Assistance in a Duel (2004)
Samurai Justice: The Female Bodyguard

Overview
A chance encounter on the road leads to the unusual need for a female bodyguard to protect the granddaughter of an old friend of Akiyama Kohei, a wealthy merchant who plans to bypass his son-in-law as head of the company. When Daijiro’s wife Mifuyu takes on the job strange things start to happen, including the brutal slaughter of company employees. With the backing of Lord Tanuma, a chief elder on the ruling council, Kohei, Daijiro, and Mifuyu form a plan to foil the kidnappers plot and save the girl from certain death.
Similar
A Matter of Valour (1957)
Gate of Hell (1953)
Chûshingura (1962)
The Sword of Doom (1966)
Taboo (1999)
Hana (2006)
Love and Honor (2006)
Incident at Blood Pass (1970)
Bored Hatamoto: The Million-ryo Mystery (1954)
The Tale of Zatoichi (1962)
Mumon: The Land of Stealth (2017)
Hanzo the Razor: Sword of Justice (1972)
Sure Death 6 (1996)
Hanzo the Razor: The Snare (1973)
Hanzo the Razor: Who's Got the Gold? (1974)
The Beauty and the Dragon (1955)
Lone Wolf and Cub: Baby Cart at the River Styx (1972)
Shadow Warrior of Nobunaga Oda (1996)
Detective Heiji (1990)
Zatoichi on the Road (1963)