Tokyo's benchmark Nikkei index climbed almost 1.9% higher today to close at a fresh 15-year high on hopes for a Greek bailout deal.
The Nikkei 225 index soared 381 points to close at 20,809, after busting through 20,700 for the first time since April 2000.
The Topix index of all first-section issues was up 1.69%, or 28 points, at 1,676.
The gains followed rallies in European and US markets.
Euro zone leaders said they hoped to finally seal a deal this week to save Athens from default and a possible messy exit from the euro, but Germany warned that more hard work was needed.