One of the Japan Sumo Association’s better-known rules is that there must be at least two ōzeki on the banzuke rankings at all times.

When a situation arises in which there aren’t enough rikishi at the sport’s second-highest rank to occupy both the east and west sides of the banzuke, one (or two) yokozuna can be designated as yokozuna-ōzeki to ensure compliance with the aforementioned rule.

Such was the case in the just-completed Nagoya tournament, where newly promoted grand champion Onosato had to cover the empty ōzeki slot created by his own elevation to sumo’s highest rank.