The benchmark 10-year JGB yield was flat at 0.770 percent, while the 10-year JGB futures contract inched up 0.02 point to end morning trade at 144.10.
The yield curve slightly steepened as longer maturities continued to underperform.
Yields on 30-year debt added half a basis point to 1.960 percent, retracing Wednesday's high, which was their highest level since April 5.
Yields on 20-year bonds also added 0.5 basis point to 1.70 percent.
"There are potential buyers in the superlong sector, particularly life insurers, but everyone appears to be holding off until after the BoJ," said a fixed-income fund manager at a European asset management firm in Tokyo.
At next Tuesday's meeting, sources have said the central bank is leaning towards deciding on additional easing steps.
The BoJ now buys bonds with up to three years left to maturity in its asset purchase programme, which has keep yields of shorter maturities steady.
The Ministry of Finance offered 2.7 trillion in 2-year notes with a coupon of 0.10 percent, matching the coupon at the previous 10 sales and also matching the interest the central bank pays on its current account excess reserves.
The latest 2-year JGB was untraded on Thursday, with its yield last at 0.10 percent.