Set in the context of Japan's extraordinary 20th-century history, the life of the emperor (1901-89) who, on his succession in 1926, hopefully chose the name ""Showa"" (""Enlightened Peace"") for his reign. Since Japan had been a constitutional monarchy since 1889, Hirohito's role as figurehead was never in doubt; as the reigning descendant of the Shinto gods, he was also revered as a god. An intelligent young man whose greatest interest was marine biology (he published papers and was a member of the British Royal Society), he welcomed opportunities to escape sequestration and learn about the world; after the occupation, however, he reverted to the reclusive life dictated by custom. His part during WW II remains an enigma: he opposed the events that led to it, yet lacked the power and/or will to interfere with its course until the end, when he decisively counseled bowing to the Allies' overwhelming force. The Hooblers' account is clear and sympathetic, though hampered by lack of available information to give their portrait depth. The picture of Japanese politics and culture is fine as far as it goes, focusing in the prewar years on the military--as it responded to population pressures, the need for raw materials, and its own heroic tradition by rampaging out of civilian control--and, in the postwar era, on Japan's economic and technological explosion. The reasons for the mind-boggling contrast between these two periods are not really addressed, though perceptive readers may conclude that the rage to preserve honor that fueled kamikaze raids has found a more constructive outlet. Thoroughly worthwhile. Bibliography; index; illus. with 32 b&w photos.