East Shinjuku is really two a daytime quarter of department stores, vertical malls, and discount stores, and a nighttime quarter of bars (straight and gay), cheap restaurants, strip joints, game parlors, jazz clubs, rooms-by-the-hour hotels, raves, and honky-tonks most of the latter in a seedy, neon-lit neighborhood called Kabuki-cho.
By day East Shinjuku is known for its shopping, by night it's known for its bars and strip clubs. 
East Shinjuku doesn't have any night time activities, there is an early cerfew. 