The Bar/Lounge at Shinjuku Granbell Hotel
Shinjuku Granbell Hotel's bar/lounge is referenced by experts. Out of 3 reviews tracked on TripExpert, 2 praised the bar/lounge, like Time Out and Oyster.
Shinjuku Granbell Hotel 
Time Out
Oyster
Time Out "Opened in late 2013, this stylish Kabukicho hotel hosts an art lounge featuring periodic exhibitions displaying the work of up-and-coming artists from all over Asia, while gigs and other live events also take place here"
Oyster "On-site features include a restaurant, cafe,
bar, art gallery, and free Wi-Fi throughout, but there's no pool,
spa, or fitness center"
