Tokyo stocks opened lower Monday as sentiment was dented by a firmer yen after weaker-than-expected U. S. nonfarm jobs data for July. At 9:15 a.m., the 225-issue Nikkei Stock Average plunged 147.34 points, or 1.02 percent, from Friday\'s close at 14,318.82. The broader Topix index of all First Section issues on the Tokyo Stock Exchange was down 9.09 points, or 0.76 percent, at 1, 187.08.