Ugh. Yeah, you can see those negative interest rates in Japan. For 10-year government bonds.
Natto Sumo YouTube Channel - main way I watch the bouts.
Video of one day of matches:
NHK World — one of their Sumopedia videos, on gold star victories
Two Facebook groups on Sumo:
SumoSumoSumo (very active, and my fave sumo group) and
NHK World’s Grand Sumo group (not very active, but official).