A Brief History of Ultraman

The original Ultraman television series debuted in 1966, and although it looks pretty cheesy to our sophisticated, 21st-century eyes, it mutated and replicated into dozens of movies and TV series, to the point where the Ultra Series (the umbrella term for all the Ultra franchises) has been recognized by the Guinness Book of World Records as the franchise with the largest number of spinoffs, and the producers recognize no fewer than 36 different Ultramen.
The original TV show, available on Hulu and as a DVD box set titled Ultraman: Complete Series, was produced by Tsuburaya Productions, the special effects studio founded by Godzilla co-creator Eiji Tsuburaya. It’s not hard to see the shared DNA. The premise is basic 1960s TV sci-fi, so prepare to suspend your disbelief hard: Giant monsters periodically threaten the earth, and their presence is monitored by the elite Science Special Search Party, which is basically five people with a couple of really cool planes (one of which has a submarine attached) and one of those big retro computers with all the blinking lights.
In the first episode, a giant, glowing ball appears and smashes into the plane being flown by SSSP pilot Shin Hayata. They both go down in a ball of fire (as witnessed by a group of grade-Z actors having a cookout nearby), but then an alien appears and fuses with Hayata in order to save his life. He gives Hayata a Beta Capsule (a glass tube that looks a bit like a cigar) that he can use to transform himself into the giant, silver-armored Ultraman. Hayata puts it to good use right away, fighting a giant reptilian monster that has suddenly appeared in the lagoon where his plane crash-landed.
And so it goes for the 39 episodes: A monster appears; Hayata transforms into Ultraman to fight it. Despite his height (40 meters, or about 130 feet) and his superpowers, Ultraman has one serious vulnerability: He can only remain on earth for a short time, after which he must either go into outer space or revert to human form. The first superhero to come with his own timer, Ultraman has a glowing light on his chest that starts out blue and turns red when his time is running out. In the last episode, spoilerifically titled “Farewell Ultraman,” he pushes it a bit too far and runs out the timer, causing him to go into a dormant state; in order to spare Hayata’s life, the alien separates himself and leaves Hayata as a normal man again.