The key Nikkei 225 added 0.53 percent or 117.03 points to 22,309.07 in early trade, while the broader Topix index firmed 0.47 percent or 7.88 points to 1,695.03.

"The Tokyo market is expected to trend higher at the start after seeing how US shares finished up," Okasan Online Securities said in a note to clients.

"But the market is likely to stay trapped in a tight range since it's easy for a wait-and-see attitude to emerge among investors with the dearth of fresh news in the market during the slack summer season," it added.

The dollar bought 110.84 yen, nearly flat from 110.90 yen in New York.

Among major shares, Toyota added 0.31 percent to 6,796 yen, after reports that it was planning to boost production capacity in China, particularly for environmentally friendly vehicles such as electric vehicles and hybrids.

Sony rose 1.21 percent to 6,019 yen, while SoftBank added 0.70 percent to 10,055 yen.

Mitsubishi UFJ Financial Group rose 1.09 percent to 665.7 yen.