Stocks in Tokyo rose in Friday morning trading following the European Central Bank\'s announcement of an emergency bond-buying programme aimed at helping to end the eurozone\'s debt crisis, dpa reported. The benchmark Nikkei 225 Stock Average rose 151.98 points, or 1.75 per cent, to trade at 8,832.55 at the end of the morning session at 11:30 am (0230 GMT). The broader-based Topix index was up 11.19 points, or 1.56 per cent, at 730.19. European Central Bank chief Mario Draghi on Thursday announced that the bank would purchase sovereign debt as a way of stemming the borrowing costs of cash-strapped euro members. Japanese stocks were also boosted by a rise on Wall Street and the weakening of the yen. On currency markets at 11:30 am, the dollar traded at 78.89-90 yen, up from Thursday\'s 5 pm quote of 78.42-44 yen. The euro was quoted at 99.65-70 yen, up from 98.92-96 yen late Thursday, and at 1.2631-34 dollars, up from 1.2614-16 dollars. A weaker yen makes Japanese goods less expensive overseas and improves repatriated earnings.