Empire of the Sun by J.G. Ballard. Categorized as a novel, technically, Ballard calls EOTS "for the most part... an eyewitness account of events I observed during the Japanese occupation of Shanghai and within the camp at Lunghua" (from the Foreward). As autobiography is often described as fiction anyway, it is fitting that this is a fictionalized story of his experience as a young boy in China and Japan during the Second World War.
Interesting note: it was made into a movie in 1987 by Steven Spielberg and starred a young Christian Bale. Even more interesting is that the screenplay was penned by Tom Stoppard!
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