Bank of Japan Gov. Haruhiko Kuroda should stay on for a second term to handle the potential fallout from five years of unprecedented monetary easing, according to the leader of an opposition party and former official at the central bank.

"I think he should stay on, but not in a positive way," Kohei Otsuka, 58, said in an interview Wednesday at his Democratic Party's offices in Tokyo. "He hasn't reached his targets and he risks a legacy of even more serious problems, so he should take responsibility for clearing things up."

Prime Minister Shinzo Abe said over the weekend that his decision on the BOJ governor remains a blank slate, but the 73-year-old Kuroda is widely expected to be reappointed after his term expires in April. His drastic policies have aided economic growth and weakened the yen, helping to push stock prices to levels not seen since the 1990s. Even so, the bank remains far from its 2 percent inflation goal.