Nakano B-kyuu is an Izakaya style restaurant (or a traditional Japanese inn) that can be found east of Nakano station [/ poi], so if you want to have something here you now know the nearest station.
It is small, but very cozy. The staff are very friendly, but don't expect any frills or fanfare from the decoration. It has two floors: the downstairs hosts the kitchen, the bar and a few tables, and the upstairs has the dining room with just half a dozen tables very close together. The food is in the style of a Japanese tavern (like yakisakana and yakitori).