Tokyo stocks opened 0.20 percent higher on Tuesday, tracking a gain in US markets, while a weak yen helped sustain exports-oriented shares.
The benchmark Nikkei 225 index rose 29.98 points to 15,160.50 at the start.
US stocks Monday finished higher, gaining force from a more optimistic perception of conflicts in Ukraine and Iraq.
The Dow Jones Industrial Average rose 0.10 percent at 16,569.98, while the broad-based S&P 500 gained 0.28 percent to 1,936.92.
The dollar was at 102.24 yen in early Tokyo trade, compared with 102.21 yen in New York late Friday.
On Monday, the dollar rallied against the yen and euro after the unit plunged in the wake of last week's announcement that Washington had authorised air strikes in Iraq.
A weak yen is good for Japanese exporters, making them more competitive overseas and inflating their repatriated profits.
The euro bought $1.3384 and 136.81 yen against $1.3383 and 136.79 yen.