Shares in Tokyo fell sharply Monday, on concerns that Japan's next prime minister could adopt policies that wouldn't be very friendly to the economy and markets. The benchmark Nikkei Stock Average fell 4.8% to 37919.55 after Shigeru Ishiba, who has been seen as favoring tighter fiscal and monetary policy, won the ruling party's leadership election on Friday. Analysts said Ishiba's previous comments about potential increases in corporate and financial-income taxes raised concerns over corporate earnings and consumer sentiment.