The greenback was trading at 122.82 yen in Tokyo, up from 122.30 overnight in New York, and has now risen 6% in a month, reducing the cost of Japan's exports. Shares in car makers and component suppliers soared an average of 5% in the wake of the yen's fall, while technology counters were also speeding ahead. Toyota, up 5.3%, and Sony, ahead by 6%, set the pace among the winners from the weaker yen.