At 3 a.m. on Monday, as most of Japan slept, news started filtering through that yokozuna Hakuho, arguably the greatest wrestler in the 2,000-year history of sumo, had decided to retire.

The strangeness of the timing, and the fact that the grand champion’s friends and family seemed caught off-guard by the announcement, led to a day of swirling rumor and speculation. The stunning news was finally confirmed by Japan Sumo Association officials on Monday evening, much to the chagrin of writers and television producers anxiously hoping to meet their early deadlines.

It was an unusual end to a career — but perhaps a fitting one for a rikishi whose achievements both inside and outside the ring continuously broke new ground.