Sumo wrestling tour information needed?

According to the website http://www.sumo.or.jp/eng/jungyo/index.html there is a tour for sumo wresting. We are visiting the end of March and beginning of April--and would like to see an event. Does anyone have more information, or where I can buy tickets? The website gives a phone number for more information, but it says you have to speak Japanese. We will be in Japan "after" the official March tournament, so wont be able to attend that.