Complex sentence: In the TV show, Hongo travels abroad to fight Shocker in other countries, leaving Japan's protection to Hayato Ichimonji, a freelance cameraman who was experimented on by Shocker but saved by Hongo, becoming the second Kamen Rider.
Split into simpler sentences: In the TV show, Hongo travels abroad to fight Shocker in other countries, but leaves Japan's protection in the hands of another man, Hayato Ichimonji. He was a freelance cameraman who was experimented on by Shocker, but was saved by Hongo, becoming the second Kamen Rider.