Investors in Japan's government bond market are getting a glimpse of life without heavy intervention by the Bank of Japan, which is showing little sign of reverting to a hands-on approach despite the recent steady rise in long-term interest rates.

The asset class is pricey, but yields are attractive and risks from inflation are lower than investment grade bonds.

Bank of Japan Gov. Kazuo Ueda promised to respond to abnormal rises in bond yields, as expectations for monetary tightening sent Japanese government bond yields to multiyear highs.

The Bank of Japan stands ready to ramp up government bond buying if long-term interest rates rise sharply, Governor Kazuo Ueda said on Friday after recent increases in yields to their highest in about 15 years.