Just one station of Shinjuku on the JR Sobu line, Okubo has one of the largest Korean, Chinese and South-East Asian community in Tokyo.
The atmosphere is definitely closer to Seoul or Bangkok than Ginza, but that gives Okubo some kind of exotism expressed in Chinese groceries or Korean BBQ and bibimbab restaurants.
The area is also notorious for its density of love hotels and adult entertainment, although it is much quieter than Shinjuku's Kabukicho.
Although the station is named Okubo, the neighourhood just around it where most of the action takes place is called Hyakunincho (百人町, meaning "100 people's town").