But gains were limited by continuing concerns about the outlook for the world's second-largest economy. Gross domestic product data released last week showed a greater-than-expected downturn in capital spending.
''Capital spending has been propping up the economy,'' said Katsuhiko Kodama, senior strategist at Toyo Securities.
''With those numbers weak, it makes institutional investors reluctant to buy. Investors want to see results from the new fiscal year, at the very least first-quarter earnings.'' The Nikkei was up 59 points at 17,615.87 as of 0622 IST. The broad TOPIX index was up 0.44 percent.
Sony continued its recent run, adding 2.7 percent to 7,130 yen.
The electronics company surged more than 6 percent over the previous five days, after it forecast a six-fold climb in group profit for this year.
Sumitomo Mitsui, Japan's third-largest banking group, gained 3.8 percent to 1.1 million yen after it said its earnings would rebound this year.
The lender said group net profit for the year just ended fell 36 percent to 441.4 billion. But it forecast a 22 percent rise, to 540 billion yen, for the 12 months to next March.
REUTERS KK PM0705