The five-year JGB yield fell 1 basis point to minus 0.170 percent, while the 10-year yield dropped 1.5 basis points to minus 0.050 percent. The 30-year yield declined 1 basis point to 0.535 percent .

Longer-dated JGBs benefited as the Bank of Japan on Monday offered to buy 230 billion yen ($2 billion) of 10- to 40-year bonds at a regular operation.

Japan's Nikkei was down 0.2 percent, losing steam after scaling a four-month peak.