Is the joke here that Nitori was hit with an automatic ring out?
No, the joke is that Marisa needed to know which direction was west to find the treasure. The kappa wouldn't tell her, but as part of the standard sumo match intro, they indicate Nitori's on the west side of the ring, so Marisa heads off into the west.
Toward the west, Nitori Kawashi-DirectionBut the compass isn't working here.It says here "advance hundred steps to the west and dig the ground".Why should we tell you knowing that you will steal it?Haha, challenging a kappa in sumou? What an idiot.Eh? ...Well, that's fine for me.Marisa was hunting for the treasure at the Kappas' secret hideout.You won't have a single chance.Can you tell me the direction?Then will you tell me if I beat you in sumou?Secret