Like many, I initially confused Gokai with Go, another fifth-floor hideout on Meiji-dori going toward Shibuya. Having ascertained that it is in the building next to the crepe shop on the corner of Takeshita and Meiji-dori, I then thought people meant Bar Poor, another cavelike perch with hobbit-sized seating on the fourth floor.
But no: Gokai is one floor up from Bar Poor's white door, which bears the word "tattooing" and a chain wrapped around its handle. Sometimes you will find a sign on the mid-floor landing above, saying Five (in kanji) F (as in, floor). Other times, illumination drops suddenly three stairs beyond. There is nothing to indicate you have arrived and often nothing to indicate it is open.
Beyond this enigmatic portal is another world. Brian Eno's was green; this one is swathed in shadow. Candles flicker along the bar and a sky of egg-shaped incandescent bulbs glow, rather than throw light, above an odd assortment of low-set tables and cushions. Each area is vaguely defined by tresses of black rope, which spew forth from the egg-spangled heavens. Bits of straw and twig lie scattered underfoot. A tree trunk leans into the bar.