Among the tokusatsu TV shows we enjoyed as a kid, we had series which featured ninja as one of them is Masked Ninja Akakage produced by Toei Company.
Another one we had and I remember even now is Ninja Hattorikun (1966: 26 episodes) produced by Toei Kyoto Television Production. The series was based on the manga drawn by Fujiko Fujio to be widely known as the author of Doraemon in later years.
Of all things, it was produced as a live-action drama series instead of anime, and it was about a ninja boy named Hattorikun (kun is a Japanese honorific title usually for boys) while the name came from Hanzo Hattori alleged to have been a real ninja in the samurai era.
As is often the case with the Fujiko manga, it is a story about the boy ninja who started living with a family in Tokyo after coming from Iga alleged to have been the home of ninjas, real-life area located in Mie Prefecture.
Among other things, it was funnily impressive to find a mask similar to the manga Hattorikun was applied to the live-action character as his real face while, surprisingly enough, he was acted alternately by the twin kid actors Mitsunori and Yoshinori Nomura who appeared in Kaiju Oji with Mitsunori as the protagonist Takeru.