[samurai007]

He will almost definitely face pressure to drink in Japan. Friends and co-workers will want to take him out to celebrate his new job and arrival in Japan, etc. I recommend telling them up front that he can't drink, have plenty of other beverages available (and ready for the kampai/toast), and make sure to try and visibly have fun and get involved at the parties (eating, singing, chatting, etc) The more outgoing he is, the less pressure there will be to "have a drink to loosen up". Go with him to these enkais if possible so that he has your support to back him up if he weakens.