Shin Ishu Kakutou Taisen

Hagane earns recognition as the world's strongest after claiming victory in a high-stakes mixed martial arts competition. Soon after, a mysterious individual contacts him, casting doubt on his title. Accepting the challenge, Hagane travels with this person to an unfamiliar location where he encounters an unfamiliar form of combat. There, he is pitted against powerful natural predators, including large elephants and lions.