Tokusatsu: Zongzi from the Start, but I'm a Showa-Era Old-Timer

Good news: He transmigrated. Bad news: After transmigrating, he was taken by an evil organization and turned into a test subject. Good news: He escaped the evil organization. Bad news: He ended up in another world full of man-eating monsters. When Monyak Jun opened his eyes again, he found himself reborn on an island nation in the Showa era. He thought he could use the experience from his previous life to make a name for himself, but then the worst happened: he was kidnapped by Great Shocker. After escaping the evil organization, Monyak Jun thought he could finally live in peace. Then he discovered he had arrived in the world of Kamen Rider Amazons, and his modified body began to unleash its power.