Bonds will probably show a gradual decline toward when the central bank will shift monetary policy. The possibility of a policy shift will stay in the minds of investors, preventing them from buying debt.
It is very doubtful the 10-year yield reflects the outlook the central bank will soon change monetary policy. It is hard for investors to buy debt when the economy has strong growth momentum.
The Bank of Japan will try its best not to cause any opposition from the government about a shift in monetary policy.