If there is a tournament on then you should go! Get a seat upstairs not a box, go between 3-6. Don't run up the stairs. Might be worth renting radio of English translations. Correlate with Wikipedia.
Exciting stuff. Come early, as it may be hard to find your seat. You'll be sitting on the floor, so don't wear a miniskirt unless you want to flash everyone there.
Awesome space! Come early and grab day tickets, but the evening sessions for the high ranking rikishi are the best. Read up some history + rules for sumo before you go, to maximise your enjoyment!
Time flies here. Experience is unforgettable so try it once in a life at least. Start early to see the difference between juniors and masters, both will bring you joy.
Sumo wrestlers appear to be demigods to the Japanese. Join the crowd at the entrance to cheer the wrestlers being dropped of by car ("similar to the oscars red carpet!").
Arrive no later than 7:00am if you want to try to get general admission tickets for that same day. If you aren't able to get tickets, there are sometimes same day box seats made available.
Second floor seats are good to get a good view! Don't need to spend more to be closer to the action, the atmosphere is great everywhere! Watch out for the Ganji wrestlers!
Sumo matches are held at Kokugikan in January, May and September. The first match was held over 1500 years ago. It's still the most popular sport in Japan.