Here's footage from 1950 showing two Japanese men in a sumo wrestling match in a ring. 

The two wrestlers are bulky yet muscular. They both wear what's called a mawashi, a kind of thong, which is really a long silk cloth that wrestlers wrap around their loins; but both men are otherwise nude. 

The clip begins with the caption "WRESTLING SUMA STYLE" and shows both men lifting up their legs in an exaggerated manner, as if to secure their place in the ring. With a referee standing nearby, they squat and look at each other intently before charging and grabbing each other. Both quickly move to the edge of the ring and, in an attempt to lift each other up, both fall out of the ring simultaneously and into the crowd. The fall looks painful, yet both men calmly pick themselves up as if it nothing happened and walk back into the ring. The audience appears unfazed. 

In the final scene, one man manages to the push the other man to the edge of the ring and forces him to bounce onto his butt. The filmmaker plays back this scene several times and adds humorous bouncing sounds as well as a metal klinking sound to underline the sumo wrestlers fall. 

The entire clip is accompanied by the voice of a man making funny, sarcastic remarks.