>>19468173It was a marketing gimmick made up by Inoki to suggest wrestling was the strongest fighting style. He would bring in fighters from various backgrounds (boxing, judo, etc) and have worked shoots. The famous Mohammed Ali match was an example, but they usually went much smoother. Inoki paid, the professionals took a dive, the fans cheered. Easy work.
It was an evolution from the earlier bouts between Rikidozan and judo legend Masahiko Kimura, where supposedly Rikidozan shot on Kimura in a match and pinned him for real.
Eventually it became a loose style of sorts where Inoki's students would mimic his miraculous fighting spirit by no-selling attacks and whatnot. Inoki eventually worked himself into a shoot and thought it was real, he put his guys in actual MMA matches and forgot to pay the legit guys to lay down. Hence the early 2000's where NJPW nearly went bankrupt.