Shikakui Jungle

Originally, it was a martial arts manga that mixed fiction and non-fiction, in which the main character, Ushio Akaboshi, a karate fighter, went to America in pursuit of his missing brother. There he witnessed the strength and variety of martial arts in America, and he set out to defeat Benny Youkide, the man who defeated his brother. The manga was a documentary-style work with a mixture of reality and fiction, involving not only martial arts but also Kyokushin Karate led by Oyama Baidatsu, New Japan Pro-Wrestling led by Antonio Inoki, and new martial arts led by Kurosaki Kentoki.

(Source: Wikipedia Japan, translated)