Japanese government bond prices were mostly higher on Tuesday, with the superlong sector outperforming on rising expectations that aggressive easing steps by the Bank of Japan would include purchases in that zone.

The Nikkei newspaper reported that BOJ Governor-nominee Haruhiko Kuroda might launch new monetary easing steps as soon as he takes office next week, even before the bank's regular policy board meeting in early April.

"We can't say that this will happen based just only on a report, but there are clearly market expectations of more easing," said Barclays Securities Japan strategist Noriatsu Tanji.

Longer-dated maturities also benefited from buying by pension funds and life insurers before the March 31 close of Japan's fiscal year.

Confirmation hearings for the two BOJ deputy governor nominees continued in the upper house of parliament on Tuesday. Hiroshi Nakaso, one of the nominees, said current economic conditions in Japan allow for the central bank to continue loosening policy further.

The other nominee, Kikuo Iwata, said that purchasing long-term government bonds would help the BOJ reach its 2 percent inflation target in two years.

Minutes released on Tuesday from the latest BOJ meeting last month showed that some board members had considered buying JGBs with longer remaining maturities as an option.

The 10-year yield fell 2 basis points to 0.635 percent, moving back towards a near-decade low of 0.585 percent hit last week.

Ten-year JGB futures rose 0.17 point to 145.14, ending just a few ticks shy of their session high and inching closer to a record high of 145.50 hit on Friday.

Expectations of aggressive BOJ stimulus also helped the dollar rise to a 3-1/2 year high of 96.71 yen.

The 20-year yield slipped 3 basis points to 1.600 percent, moving back towards a nearly 10-year low of 1.450 percent hit last Tuesday, even as a sale of 1.2 trillion yen of 20-year bonds loomed on Thursday.

The 30-year bond yield dropped 3.5 basis points to 1.745 percent, reapproaching a 2-1/2 year low of 1.625 percent hit on Tuesday.

The five-year yield was half a basis point higher at 0.115 percent, consistent with its morning level as the Ministry of Finance offered 2.7 trillion yen of notes with that maturity.

The coupon on the latest offering was 0.1 percent, matching the record-low coupon of last month's offering. The sale had a lowest price of 99.89 and bids of 3.12 times the amount offered. That was down from the previous sale's bid-to-cover ratio of 3.81 times, and the lowest since June.

The tail between the average and lowest accepted prices was 0.01, matching that at last month's offering.

"Five-year auctions are uneventful these days because demand is steady, as there's no risk of holding them, but rewards are also small, with the yield already scraping recent lows," said a fixed-income fund manager at a Japanese asset management firm.

The five-year yield skidded to a record low of 0.095 percent on March 4.

(Reporting by Lisa Twaronite; Editing by Chris Gallagher)