Book excerpt: Despite its prominence in world finance, Japan's stock market has remained an enigma to many investors. This book aims to remove the mystery, revealing how Japanese corporations have moulded the market into a cheap source of capital; why most shares of corporations are held by other corporations; what the Keiretsu - secretive stockbroking, insurance and banking cartels - really do; and how the market's 1990 collapse affected these interlocking relationships.