The Nikkei 225 index has closed at 10,633.72, up 186.18 points, following Wall Street's overnight gains.
The dollar was at 121.62 yen in Tokyo trading, up from 121.60 in late New York trade; and at 0.8969 against the euro, compared with 0.8968 in New York.
Dealers say trading was rangebound ahead of the today's meeting of the US Federal Open Market Committee, at which interest rates are widely expected to be cut.
Government bond prices closed unchanged, with the yield on the 10-year No 234 issue quoted at 1.3%, while the yield on the No 233 issue was 1.25%.