Dojinkai has long been one of Japan’s top organized crime syndicates, or yakuza, brethren of the American mafia. When it came to the all-important social rules governing Japanese neighborhoods, the Dojinkai was neighborly enough that a young hairstylist did not hesitate to open a fashionable salon, complete with music by Enya, a stone’s throw away from the headquarters.But residents began worrying two years ago after factional fighting spilled out onto the streets, one time with machine gun fire and explosions.More than 600 residents recently went to court to oust the Dojinkai from its six-story headquarters, located in a prominent commercial area near the main train station in this medium-sized city in western Japan.The lawsuit was the first of its kind in Japan, where the yakuza’s offices tend to be out in the open. It shined a spotlight on how the yakuza — long considered a necessary evil, tolerated by, and sometimes politically allied with, the authorities — occupy a place much clo...