Get tickets and join the crowds at a game at Nippon Budokan. If there's nothing on while you're there, you might like to check if the stadium offers a tour of the facilities.
Nippon Budokan charges admission, so grab some cash and find your way to the historic ward of Chiyoda. Wondering where to next after the sporting facility? Tokyo Sky Tree, Tokyo Tower and Tokyo Imperial Palace are a few nearby attractions worth a visit if you've still got time.