Typical place to enjoy alcohol in Japan is IZAKAYA style tavern but izakaya is more likely a place to eat food too. If you had a dinner at sushi bar and want to drink western alcohol where you should go?
The answer is bar. Bars in Japan are smaller than izakaya and sometimes not easy to find. Even if you could have found it, may be it is not easy to go inside. If there is no other customer, you might think the bar is expensive. On the other hand, if there are other customers, you might hesitate to join them.
Although many bars do not have price lists on the door, the prices are reasonable and people are very friendly. Then, bar is a place rather to enter alone than going with your friends.