Tokyo stocks rose after Prime Minister Shinzo Abe postponed a planned sales-tax hike, called a snap election and said Japan would adopt another stimulus package.
The Nikkei 225 index, which turned up more than two per cent on Tuesday after tumbling a day earlier, gained 40.25 points to 17,384.31 at the start.
The higher opening at the Tokyo Stock Exchange came after the US dollar rose to 117.14 yen early Wednesday from 116.83 yen in New York Tuesday afternoon and 116.57 yen in Tokyo earlier Tuesday.
A weak yen is positive for Japanese exporters as it makes them more competitive abroad and increases profits when repatriated.
The market remained solid after Prime Minister Shinzo Abe on Tuesday called for early elections to seek a mandate for delaying next year's sales tax increase and his economic policies.