Kamen Rider Amazon

Amazon, a wild youth in the jungle, is remodeled by the ancient Inca science. With the "Bracelet of Gigi," the key that opens the door to the hidden treasure, on his arm, he protects the treasured ordnance and weaponry, as well as the future of mankind! The enemy is Gorgoth, a ten-faced demon who plans to conquer the world with the "Bracelet of Gaga," an opposing key!

(Source: MangaDex)

Kamen Rider Amazon was first compiled in volume form in 2001 by Futabasha, where it was included in the volume "Kamen Rider EX" with a "storyboard manga" version of the original Kamen Rider series and other extras.