Do they have Korean music stores or Korean merchandise there ? This is moot because, as the others have said, there is no Korea Town (or any *predominantly* Korean neighborhood, for that matter) in San Francisco. There is the occasional Korean store in various parts of the city, though (Sunset, Richmond, probably Japantown area, etc...)
No its not. There is a concentrated community of Koreans around Japantown but its not official. And there is a small stretch in downtown Hayward that s filled with Korean restaurants and grocery stores.
NOPE!