One of a chain of pubs run by Sapporo Beer, this one is located right off Dogenzaka in Shibuya. It could, however, be a difficult place to find since it is located on the second floor and virtually unviewable from the sidewalk. The Dubliners’ Cafe & Pub – Shibuya.
When I visited there with some friends, there was live Irish music. A trio, including a fiddler, was performing that night on the balcony. It was a bit surreal since the pub is in the heart of Shibuya, the center of youth culture in Japan, but it was nevertheless very pleasant. And since Sapporo distributes Guinness Beer in Japan, you never have to worry about it running out!