When I think about Japanese TV shows which became unlikely hits overseas, "Monkey" (西遊記) is the first which come to mind. Over 10 years earlier, however, Australia also fell in love with a different series. An article from 1966 explains:

A clip from a show which looked at the phenomenon.

If you have a spare 50 minutes, that whole documentary, which is an affectionate look at the way the show swept Asutralia, is on Youtube, in two parts.

Ninjas and swordplay were all new at the time but the onsen scenes also affected impressionable young Australian minds.

It became a merchandising opportunity for Australian toy and confectionery companies.

One of the best parts of that TV retrospective covers the time the leading actor, Koichi Ose, visited Australia.

Koichi Ose recalling the visit. He thought dressing up as his character to get off the plane was a cheesy idea but soon realized it was exactly what the children wanted to see.