Originally, not sports, it was an act of God that a man with the power gave the power to in in front of God. Therefore manners to show respect for God are made much of.
Because they compete for the superiority and inferiority only with the body of the contestant without using a tool in a nude body, it is the competition of the wrestling system, and, for the system of sports, it is transcribed in the English with "Sumo-Wrestling".
We call the competition of the martial art to grapple together sumo generally in Japan. There are arm wrestling, leg wrestling, finger wrestling for an example.
In the following example.
Person 2: (He does not know what to say) Sumo dear sumo.
Person 1: I knew you didn't think that way. I am so hurt, help me. (Hugs)
The meaning of sumo depends on how the other person want to interpret it.