Ultraman 80 is a Japanese tokusatsu TV show produced by Tsuburaya Productions which aired on the Tokyo Broadcasting System channel from April 2, 1980 to March 25, 1981, lasting a total of 50 episodes. It was the ninth TV show in the Ultra Series and began a week after the conclusion of the anime series The Ultraman, bringing the franchise back to its live-action roots. It would be the last Ultraman TV series for Japanese audiences during the following sixteen years until the production of Ultraman Tiga.
Plot of the series: Ultraman 80 comes to Earth as one of the newest members of the Ultra Space Garrison (it is revealed in Ultraman Mebius that he is the ninth Ultra Brother), in the form of science teacher Takeshi Yamato. After a five-year hiatus since the departure of Ultraman Leo (1974), monsters started reappearing again.
More information: http://ultra.wikia.com/wiki/Ultraman_80_(series)