The benchmark 10-year JGB yield was 1 basis point higher at 0.010 percent after rising to 0.015 percent earlier. The yield remained within shot of zero percent, a five-month low touched on Wednesday.

The 20-year yield was a basis point higher at 0.565 percent.

The bid-to-cover ratio, a gauge of demand, at Thursday's one trillion yen ($9.18 billion) 20-year auction rose to 4.06 from 3.78 at the previous sale in March.

The new 20-year JGBs attracted investor demand with several factors currently supporting the debt market, like tensions in the Korean Peninsula and concerns about the French presidential elections.

Treasury yields rose with their prices dipping overnight as a rally that had sent yields to five-month lows at the start of the week petered out.