Tokyo stocks fell in the morning session on Friday as investors were increasingly worried about an imminent U.S. military strike against Syria.The 225-issue Nikkei Stock Average dropped by 90.22 points, or 0.67 percent, from Thursday to 13,369.49, after it opened higher thanks to upbeat data on the U.S. economy.The broader Topix index of all First Section issues on the Tokyo Stock Exchange also edged down by 8.95 points, or 0.80 percent, to 1,107.56.