[Sangetsu]

As for Disney, you don't have to pre-book tickets. It's best to go in the middle of the week to avoid the crowd, Tuesday through Thursday would be best. It's not so crowded at the parks in the winter, as it does get cold here in Japan. The parks will be even more quiet if it is raining.

The Disney resorts are less than 30 minutes from Tokyo Station on the Keio line. The sumo arena is located in Kinshichiro, which is also close to Tokyo Station, on the Sobu line, if I remember correctly. Near the sumo arena is the Edo-Tokyo museum, which is worth seeing.