Giant Robo was a comic which was first featured in a weekly comic magazine "Shonen Sunday" in the late '60s by comic artist Mitsuteru Yokoyama, then turned into a TV series. Yokoyama drew another comic featuring a giant robot under a boy's control; the "Gigantor" (Tetsujin Nijyuhachi-go) which also became a TV series (four times). Giant Robo was supposed to be a weapon for the bad guys, but because U7 (Disuke Kusama) first spoke into the wrist watch remote control, it only obeyed his command. Like Gigantor, its first incarnation to TV was acted by a real live actors, then the second series was animated. I have memories of this series like many people who wrote here including having a crush on U5. I don't know what it is about these classic Japanese TV sci-fi but there's something that leaves a lasting impression on people. Yokoyama has another comic with giant robot obeying master's commands (Babyl II or Babyl Nisei) which also became a TV series. He is considered along the likes of Osamu Tezuka (Astro Boy), Ishinomori Shotaro (Kamen Ryder, Kikaida, Go Rangers, Cyborg 009), and Fujiko Fujio (Obake no Q-taro, Doraemon) as a founding father of genre we now call "Manga", and has legion of fans around the world. Just a great show from a great comic artist.