“We’re in risk-on mode,” Chihiro Ohta, a senior strategist at SMBC Nikko Securities, told Bloomberg News.
“Oil prices rose, stocks rose and the dollar strengthened in overseas trading. The environment is good for Japanese stocks.”
The Nikkei-225 index climbed 0.29 percent, or 47.80 points, to 16,612.99 by the break. The Topix index of all first-section shares edged up 0.07 percent, or 0.97 points, to 1,335.87.
In Tokyo share trading, mobile giant Softbank jumped 2.84 percent to 6,162 yen while Uniqlo operator Fast Retailing, a market heavyweight, slipped 0.24 percent to 28,825 yen.
Toyota rose 0.18 percent to 5,687 yen before it publishes full-year earnings after markets close Wednesday.
Troubled airbag producer Takata jumped 2.86 percent to 324 yen, despite growing concerns over its finances as it struggles with a global defect scandal. It also reports earnings later Wednesday.
In currency markets, the dollar eased slightly to 108.85 yen from 109.27 yen Tuesday in New York, but it was still up from levels seen earlier this week.