Osakans love to let loose: the city is teeming with izakaya, bars and nightclubs. Craft beer and coffee scenes are on the rise, too; see the Osaka Craft Beer Map (www.facebook.com/osakacraftbeermap). In the summertime, rooftop beer gardens open atop department stores. Check Kansai Scene (www.kansaiscene.com) for nightclub information; hostel staff and English-speaking bartenders at pubs popular with expats are another good information source.
Given that so many commuters are either coming or going through JR Osaka Station or Hankyū Umeda Station, the surrounding lanes, especially to the south and the east of the train stations, have scores of bars and izakaya. Nearby Doyama-chō is western Japan's largest gay district with some 200 (tiny) bars.
Visit Minami on a Friday night and you might think there's one bar for every resident – including izakaya, Irish pubs and cocktail lounges (as well as hostess and host bars, where the servers are flirtatious women and men, and the drinks are very pricey). Friday and Saturday nights are the big nights out (especially for clubs) but you'll usually have company on weeknights too. The English-speaking crowd tends to congregate in Amerika-Mura, which has lots of small, cheap bars that open onto the street; the nightclubs are mostly here too.
Look Up, Look Down
When wandering the narrow streets of Osaka late at night, convinced that spot you're looking for must have closed or moved, remember that bars and pubs throughout Japan are often tucked away in the upper floors and basements of buildings. Check signs on the sides of buildings showing what's on each floor and learn how to ask 'Where is…?' in Japanese (…wa doko des ka?).
Worth a Detour: Ura-Namba
Ura-Namba (literally 'behind Namba') is an unofficial district made up of clusters of small restaurants and bars in the shadow of Nankai Namba Station. It's becoming an increasingly cool place to hang out in. A good place to start is the Misono Building, a once grand (and now wilting) structure, which has dozens of bars on the 2nd floor.