Tokyo stocks opened higher on Monday morning following the U.S. dollar's rise to its highest level against the yen in five years. At 9:15 a.m., the 225-issue Nikkei Stock Average rose 24.51 points, or 0.15 percent, from Friday to 16,203.45. The broader Topix index of all First Section issues on the Tokyo Stock Exchange gained 6.85 points, or 0.53 percent, at 1,296. 92. The Nikkei index was up 6.8 percent during eight straight days through last Friday, which caused some worries over market overheating among investors.