The Nikkei added 0.84 percent, or 334.87 points, to 40,245.69 shortly after the opening bell, while the broader Topix index rose 0.30 percent or 8.07 points to 2,717.49.
The dollar stood at 150.04 yen, compared with 150.11 yen seen Friday in New York.
Tokyo and other major global shares have steadily gained since last year, and analysts predict the Nikkei should gain even further, lifted by rallying Wall Street, robust corporate earnings and strong hopes for AI technologies.
“The strong performance of global equity markets, including the MSCI World, Japanese Nikkei 225, Nasdaq, and S&P 500 indexes, which all closed at record highs last week, provide favourable trade winds for Asian markets as the new week begins on Monday,” Stephen Innes of SPI Asset Management said.
“The positive sentiment is driven by several factors, including the hope for US interest rate cuts, signs of cooling inflation, and a surge in interest surrounding artificial intelligence within the big tech sector,” he said.”These factors collectively contribute to the positive tone in global markets, which is expected to bolster Asian markets and inspire confidence among investors as they commence trading for the week,” he said.On February 22 the Nikkei finally broke through a record high set just before an asset bubble in Japan catastrophically burst in the early 1990s.
Among major shares, high-tech investor SoftBank Group jumped 2.60 percent to 9,139 yen.
Semiconductor shares rallied, adding to recent strong gains.
Tokyo Electron roared 3.15 percent to 39,590 yen. Advantest surged 2.65 percent to 7,308 yen.
Industrial robot maker Fanuc added 1.60 percent to 4,521 yen.
But Toyota gave up early gains and dropped 1.06 percent to 3,641 yen in early trade, as did Sony Group, which lost 0.91 percent to 13,095 yen.
