Asian shares kicked off the week mostly higher after a historic deal over Iran's nuclear program bolstered risk appetite, sending the yen sharply lower against major counterparts.
A strong finish on Wall Street last week also underpinned gains. The S&P 500 recorded its first close above 1,800 and the Dow posted its longest weekly-winning streak in nearly three years, as worries about the Federal Reserve curbing stimulus in December receded.
"While there aren't any major [economic] releases in Asia today, the favorable risk mood seems enough to keep driving yen weakness. Perhaps the Iran nuclear deal, effectively setting limits to Iran's nuclear program, has added to the buoyant risk mood as it is the only fresh major development from Friday's trade," said Stan Shamu, market strategist at IG.
(Read more: This week, watch Japan data blitz and India GDP)