The people in our Tokyo office, two stops away in Nakano, think the Okubo area is full of street hookers at night, but they don't go there at night so it could just be urban myth.

On my last trip, I got off at Okubo station (Chuo-sobu line, bright yellow) and walked back to the PH, which is not very far. Going in that direction, there wasn't much Korean stuff but I did find a coin-op laundry that I later used and a tiny Indian restaurant with tasty, cheap set lunches.