Tenjin is the heart of Fukuoka City, and virtually every bus or train you get on is either going to or coming from there. You'll find numerous department stores (all quite expensive), a large underground shopping area called the Chikagai which runs through most of the important street, the subway station, and the hangout of the young and the ex-pats on weekends and holidays....
Another busy shopping street is the Tenjin Shintencho, with people pouring through all day and evening.
And if you like, take a virtual walk down the full length of the Chikagai:
