Sounds like a great evening. I recall many a time when I'd wander into a neighborhood izakaya and be made to feel right at home by the owner / chef or by a few locals sitting at a table. Almost instantly.

I always felt that that was quite remarkable, since Japan is in many way a somewhat "alien" culture to our western sensibilities. But in an izakaya or a mini karaoke / "snack" bar, any obstacles to intercultural communication would disappear for the duration of our stay in those places.

Of course, the booze helps, but that's not the only thing. In an izakaya, an outsider can be made to feel welcome / at home, much more so than would happen in most bars / pubs in the west.