Single O Ryogoku Roastworks/Cafe is the most flexible eastern stop in this selection because it joins production identity with a broader café service. The current address is 3-21-5 Kamezawa in Sumida. According to the official account, the expanded format opened in 2024 after moving roughly 200 metres from the former weekend tasting-bar site. That change is important: this is not simply an old pin carried forward, but a distinct current café identity.

The official menu description includes espresso, latte and tap coffee, as well as food. Those options make Single O different from LEAVES COFFEE ROASTERS, whose Honjo location is presented as a more concentrated roastery stop with a limited weekly schedule. The two can form a useful eastern Tokyo comparison, but they should be allowed separate attention because their service formats and addresses are not interchangeable.

Single O suits visitors who want coffee to remain central while leaving room for a more varied café visit. Notice the meeting of roastworks and hospitality in the current format, and keep the former tasting-bar location from confusing your plans. The Kamezawa address, food offering and regular weekday service are the grounded reasons this Place belongs on a route through the Ryogoku and wider Sumida area.