I am afraid there is virtually no chance for sumo on that day. It is the last Saturday of the tournament, which is always a tough ticket. Advance tickets are sold out. A few will be available at the box office on the day-of but they will sell out in the morning. The last hour of the day is when the big names fight and nobody misses that. You will not get in so there is little reason to kill yourself getting there. Your best bet to see sumo is to get to a hotel room and watch the live broadcast on TV.