Tokyo stocks opened lower Tuesday after the previous day’s surge of the Nikkei index, with trading cautious ahead of the start of the Bank of Japan’s two-day policy meeting later in the day. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average fell 303.16 points, or 0.79 percent, from Monday to 38,165.47. The broader Topix index was down 14.39 points, or 0.52 percent, at 2,745.28. On the top-tier Prime Market, decliners were led by mining, bank and machinery issues. At 9 a.m., the U.S. dollar fetched 153.82-83 yen compared with 153.98-154.08 yen in New York and 153.61-63 yen …