Not sure how popular that name is. Imagine if you were trying to find John Smith on Facebook. There would probably be a lot of people who would pop up with that same name. Japan is kind of like that , many people with that same name. Often the way the name is written in Kanji is a way to tell the difference. If he ever mentioned the city he is in , that may help a little. Don't give up hoping to find him , just trying to get across to you how hard it is to find someone in Japan without a lot of info about them to help in the search. Did he go to a high school here in America with you? If so , the school might be able to help you with info they have if there no privacy rules against it. If he was in a high school in Japan talking with you , the name of the high school might help. Sorry to be a pest about more info , but searching for someone in Japan is hard.