A full autobiography recalling the author's childhood as a "B.I.J."-born (1910) in Japan (of missionary parents)-through his pioneering scholarship as a historian of Japan at Harvard, and his eventful tour in the 1960s as U.S. ambassador in Tokyo. The treatment is factual, chronological, without rancor. The chapters on the Tokyo years, which saw Mr. Reischauer survive an assassin's knife and keep Japanese-American relations on a steady course in spite of the Vietnam War, are an important contribution to diplomatic history.