While it must be stated that in Tokyo it's possible to buy sake, or nihonshu, originating from all over Japan, there's very little sake produced in Tokyo or it's surrounding areas. While the reasons for this may seem obvious, from there being not much land available for rice cultivation to the quality of the water in and around Tokyo, there are a few breweries, or kura, producing sake in Tokyo. A case in point is the Koyama brewery who produce a range of sake brewed within the famed 23 city wards that make up the Tokyo Metropoloitian area.
Located in Kita-ku to the north of the city just below the Arakawa river and a stone's throw from Akabane station, they produce 14 sakes ranging in price from an eye-watering 15,429 yen for a presumably excellent daiginjo down to a very reasonable futsū-shu at 1728 yen for a 1.8L bottle or 864 for a 720ml bottle. Guess which sake I was drinking...yes, you're right the futsū-shu.
I actually picked it up at the local supermarket, and it was the combination of being from Tokyo and rated as a karakuchi, or dry, that appealed to me. As a futsu, or 'ordinary' sake (think house wine), it's made for everyday drinking and at this task it excels. It's suitably dry with a slight rounded mouth feel. Works well across a range of temperatures from chilled to warm.
Interestingly, and considering that water quality is paramount to any good brewing, the Koyama brewery has it's own well. But the well is not situated in Tokyo, but in the mountains of Chichibu about 100km north-west of Tokyo.
On the Koyama Shuzo website as well as an easy to naviagte online shop there's a little bit about the company. It also seems they run brewery, or kura, tours every Wednesday.
I might need to do a little more exploring. A sake brewery tour here in the centre of Tokyo! What more could you ask for.