As these two are next to each other they work though there's not much to see at the latter beyond a small Sumo museum & shop on non-tournament days. I walked through the exhibits and found it an interesting diversion.

The Edo Tokyo Museum should not be missed as it's a very interesting & engaging way to learn more about the city's recent history. The Kabuki theatre and Nihonbashi bridge are two stand-out displays.

BTW I ventured past the sumo hall to Kyu-Yasuda Teien Garden and then to the adjacent memorial to the devastating 1923 great Kanto earthquake. A nice half day or so in Ryōgoku.

Also on the sake subject I quite enjoyed a tasting course at Sake Plaza which is a street level store in the Japan Sake Brewers Association Building that acts as a sake-industry information center.

For ¥500 you can select five varieties from around the country to sample and take home a souvenir a small sake cup. The staff were so polite and put on an English video of how sake is made. I quite enjoyed the visit and if interested would recommend it especially since it's very central to Hibiya Koen and Imperial Palace.