Poster for Planet Prince: The Terrifying Spaceship, released on May 25, 1959. This was the second half of a two-part serial; the first half was released the previous week on May 19.
These two short features - Part One was 57 minutes long, Part Two was 64 minutes - were produced by Toei. They were adaptations of the Planet Prince television series from Senkosha, much like Toei had done with Senkosha's previous series Moonlight Mask (Gekko Kamen).
However, unlike the Moonlight Mask films, the Planet Prince films featured a hero not at all resembling his television counterpart.
The television Planet Prince was Senkosha's answer to Shin Toho's theatrical superhero Super Giant (aka Starman in the USA), with a similar costume and superpowers. Over 49 episodes his costume changed a bit, but he looked like this:
I think we can all agree, the two versions of Planet Prince look nothing alike. Well, except that they both have the same number of arms and legs and noses and whatnot.
In 1965 the two Toei Planet Prince films were edited together into an 85 minute-long TV movie for American television entitled Prince of Space. This is the version seen on Mystery Science Theatre 3000, and was released on DVD with the Sonny Chiba (as Iron Sharp/Space Chief) film Invasion of the Neptune Men (1961).
Anyhoo, in no way should Planet Prince/Prince of Space be confused with this guy:
This is Prince Planet, the hero of a 52-episode animated series that debuted in Japan in 1965. An English-dubbed version hit American airwaves the following year.
Prince Planet was, like Super Giant/Starman and Planet Prince, and alien endowed with incredible superpowers (Although most of his came from his pendant) who came to Earth to protect its inhabitants from various threats.
The series did not last more than a year, however, because of two reasons:
It was black-and-white when color TV was rapidly gaining popularity; kids had more colorful choices for their viewing pleasure.
Parent groups complained about violence in the series, especially when Prince Planet seemed to have no qualms about killing his enemies. I have not seen this series, but I really, really want to just for that reason alone.
Finally, in 2012 there was a theatrical reboot of Planet Prince, appropriately entitled Planet Prince 2021.
I have not seen this film yet, though I did see the trailer a couple of years back and wasn't very impressed; it seemed the filmmakers were going for a goofy, "look how silly we can be" vibe, much like Monster X Strikes Back: Attack the G8 Summit (2008), the sequel/reboot of The X From Outer Space (1967).
I will seek out this film and view one of these days, though, if only because it features one of the last performances by the late Jirō Dan, who was Ultraman Jack's alter ego, Hideki Go, for decades.
Also, the costume looks kinda neat, in a low budget sorta way, although I'm not crazy about the sneakers.