In Tokyo there is one main centre for a new foreigner to look for both socializing and networking, the Tokyo American Club (TAC). However, TAC isn’t the only place in town. The British Club, having expired many years ago, left a hole that has partly been filled through and expansion of the Foreign Correspondents Club of Japan, the FCCJ.
Out of Tokyo there's the Yokohama Country and Athletics Club or its sister the Kobe Regatta and Athletic Club in Kansai. In Hiroo, the Tokyo Lawn Tennis Club sports no grass but ten clay courts and if it's the view then it has to be Roppongi Hills for dinner on the 51 floor.