It was the first Japanese TV program ever screened in Australia, where it premiered in 1964 and built up a remarkably large fan-base among the local young audience at the time, rapidly becoming a cult favourite.
Despite its massive popularity in Australia as well as success in Japan, New Zealand and the Philippines, the series was not widely screened elsewhere and its fame remains largely restricted to those countries.
Because he is the son of a concubine, Nobuchiyo has no claim to power, so he assumes the guise of a wandering swordsman named Shintarō to seek out and eliminate plots by rival feudal lords and thus protect his younger brother.
Originally it was planned to make only four distinct stories, with a different hero in each, however Shintarō was received so well that he remained for the rest of the series in which, acting on secret orders from the rōjū (high councillor) Lord Matsudaira Sadanobu, he gathers information mostly in the various fiefdoms of the central Honshū and battles rival warriors and spies, often aided by his faithful ninja assistant Tombei the Mist (霧の遁兵衛, Kiri no Tonbei) (played by Fuyukichi Maki).
The series' second main character is Tombei the Mist, an Iga Ninja master considered to be the best of the Oniwabanshū employed by the shogun to guard his castle, who first appears in the third story arc (second season in the Australian TV broadcast) and promptly becomes Shintarō's regular sidekick.
Tombei is a master of disguise, skilled with shuriken, swords (using the reverse-grip technique) and scaling hooks, also able to call-in the additional Men of Iga, and the two saved each other's lives numerous times.
Later Shintarō is also accompanied by young boy with a pet monkey - Baba Shūsaku (played by Ōmori Shunsuke, replaced by Mitsuru Takeuchi for the first film).
The lord of Matsumae suspects that this will lead to the shogunate taking control of his fiefdom and sends his fanatically loyal but rightful retainer, Kiba Jinjūrō (played by Toshiyuki Katsuki), who vows to kill Shintarō.
Also introduced to the series is Shūsaku, a descendant of the great Takeda general Baba Nobukatsu, a real historical figure, whose father has been kidnapped by the Kōga Ninja.
Set in May 1788, the story concerns the mission of Shintarō, aided by Tombei and his group of Iga Ninja, to stop Momochi Genkurō (played by Toshiyuki Katsuki), the best swordsman in Japan, and the leader of a renegade group of ten master Iga Ninja from the Manji Valley who are hired by the Lord of Owari to assassinate Matsudaira Sadanobu on the Tōkaidō road in the region between Edo and Kyoto.
To further their aims the Black Ninja begin killing "secret samurai" in Edo and in the provinces to expose the elaborate system of spies that the shogunate employs to keep tabs on the domain lords.
Shintarō foils all of the Black Ninja's plans, obtains the scroll containing the signatures of the plotters and eventually uncovers the instigator of the conspiracy and the true identity of Hakuunsai.
He is obsessed with finding the buried treasure of the Hōjō clan lost at the end of the 16th century when Odawara Castle fell to Toyotomi Hideyoshi, and using the million pieces of gold it contains to revive the fortunes of the Fūma.
This story is set in and around Edo and concerns the mysterious Lord of Night (Kurayami no Gotairō) and his attempt to bring about Matsudaira Sadanobu's downfall by destroying those closest to him.
When he fails to report, Shintarō goes after him and discovers Genshin of the Shiranui clan has been bringing in guns smuggled from abroad and distributing them to other lords in Hizen with the ultimate aim of toppling the central government and taking control of Japan.
Wearied of fighting, Shintaro, with the disenchanted Kongo (who now sees the dream of restoring the past of bloodshed and violence to be futile), leaves for another life, his mission achieved and society at peace.
As he and Kongo depart, Shūsaku, Tombei the Mist, and Oboro (Kotarō/Kongō's sister from the Fuma Ninja stories) remain behind on the shore, sadly crying out their farewells.
By 1965 it was the TV hit of the year, becoming the most popular programme in TCN-9's history up to that time, surpassing even The Mickey Mouse Club and sparking the first wave of ninja-mania outside Japan.
The program proved so popular that a promoter brought out star Ose Koichi and a large supporting troupe to appear in a specially written 90-minute stage play based on the show, which played to capacity houses in both at the Sydney Stadium[2] and Melbourne, and it was reported that more people (over 7,000, many of them in costume) turned out to greet Ose when he arrived at Essendon Airport in Melbourne than greeted The Beatles when they visited there in June 1964.
Novelist Ruth Manley took names, even characters and incidents from the show and recast and wove them into her three children's novels based on Japanese myths and folklore, The Plum Rain Scroll (1978), The Dragon Stone (1982) and The Peony Lantern (1987).
In February 2010 Siren Visual Entertainment began releasing the complete series in English (remastered, with optional original Japanese sound track with subtitles) for the first time.
[4] The first film, titled simply Onmitsu Kenshi and released on March 28, 1964, concerns a group of daimyō led by the Lord of Owari involved in a conspiracy to overthrow the shogun.
The sequel series, made by the same creators (again produced by Shinichi Nishimura, written by Masaru Igami, scored by Hirooki Ogawa and directed by Funatoko Sadao and Tōru Toyama), run from 1964 and 1965.
The New Samurai (Shin Onmitsu Kenshi) was originally aired in three story arcs on TBS between October 7, 1973 to March 31, 1974, however it failed to repeat the success of the first series.