The Vivo chain of casual wine bars offers good food and decent wines at budget-friendly prices, and the conveniently located Yotsuya branch is no exception. Ten daily wines by the glass start at around Y600, and most snacks are Y400 a pop, with no cover charge.
Yotsuya's tiny triangular bar is somewhat smaller than usual though. There's room for maybe seven or eight customers, and you may have to stand up to let other customers in or out. The big second-floor windows looking onto Shinjuku-dori keep it from feeling claustrophobic though.