By Agence France-Presse
The benchmark Nikkei 225 index rose 0.84 percent or 187.16 points to 22,358.51 in early trade while the broader Topix index was up 0.89 percent or 15.49 points at 1,764.66.
US President Donald Trump's announcement Friday that he will meet North Korean leader Kim Jong Un on June 12 as scheduled is also supporting the Japanese market, analysts said.
The dollar fetched 109.60 yen in early Asian trade, against 109.50 yen in New York.
"With the healthy condition of the US economy confirmed, the US Federal Reserve is certain to hike its policy rate," said Masayuki Kubota, chief strategist at Rakuten Securities.
"A rate hike is a double-edged sword, as the widening of the interest rate gap would produce a cheaper yen, while an interest rate hike would weigh on global share prices," he said.
Tokyo stocks would see range-bound trading after initial rallies, he said.
For this week, uncertainties about the political situation in Italy and Spain, as well lingering concerns over US protectionist trade policy, could weigh on the market, said Daiwa Securities strategist Tsuyoshi Nomaguchi.
In Tokyo, Toyota was up 1.97 percent at 7,262 yen, Sony was up 1.90 percent at 5,260 yen and Mitsubishi UFJ Financial was up 1.19 percent at 674.1 yen.