Tokyo stocks opened lower Friday on overnight falls in the US market and the yen's advance against the US dollar, according to dpa. The Nikkei 225 Stock Average fell 103.70 points in morning trading, or 0.63 per cent, to 16,310.09. The broader Topix index of all first-section issues was also down 17.90 points, or 1.14 per cent, to 1,548.94. Investors sold export-oriented automakers and technology issues as the stronger yen against the US dollar makes Japanese products more expensive overseas. On currency markets at 9 am (0000 GMT), the dollar was quoted at 114.92-97 yen, down from Thursday's 5 pm quote of 115.59-62 yen. The euro was quoted at 1.4068-73 dollars, up from Thursday's 5 pm quote of 1.4037-40 dollars, and at 161.70-75 yen, down from 162.28-32 yen.