The Nikkei closed at its highest level since November 1991 on Tuesday. The bellwether index added 0.57 percent to end at 23,849.99 points while the broader Topix was up 0.48 percent.
Japanese markets were playing catch-up after being closed Monday for a public holiday.
“With tailwind from US shares, investors were betting there’s some more room for share prices to rise,” said Okasan Online Securities strategist Yoshihiro Ito.
Investors were also in a good mood over an apparent easing of tensions on the Korean peninsula, with the first talks between North and South Korea in more than two years providing a ray of hope to many.
Abrupt end in sight?
Tuesday saw most Asian markets rising, with Hong Kong adding 0.2 percent and marking its best run of gains since October 2012, while Shanghai finished 0.1 percent higher.
“This environment of strong global growth and contained inflation is actually great for Asian equities, including tech,” said Ajay Kapur, head of the Asia Pacific and global emerging market strategy at Bank of America Merrill Lynch in Hong Kong.
But while markets in the region continue to push even higher, there are worries the advances this week could be petering out; and there are also warnings of a sharp correction on the horizon.