Gigantor—or Tetsujin 28-go ("Iron Man #28") as he was known in the land of the rising sun—was the first giant robot featured in manga, which of course means the Japanese needed to build a "life-size" version of him in Kobe as an homage to his greatness.
If you grew up in the U.S. in the '60s or '70s, you can no doubt sing you the theme song for the show, which, like Speed Racer, was a watered-down adaptation of a Japanese anime; in this case Tetsujin 28-go, based on the manga by Mitsuteru Yokoyama released in 1956.
The original black-and-white series was colorized and revived in the 1990s, meaning a whole new generation of kids will have that irritating theme song stuck in their heads for all eternity.
Anyway, back to the wacky Japanese. Here's a video of the statue they want to erect in the ancient Imperial Capital (it was the capital of Japan for about five minutes in the 12th century):