Japan's regional bank lobby called on the central bank to focus on the rising costs of prolonged monetary easing.

Takashige Shibato, head of the Regional Banks Association of Japan, said the BOJ's ultra-loose policy likely helped the economy achieve one of the longest uninterrupted post-war expansion. While various risks are clouding the outlook for Japan's economy, the BOJ must take into account the dangers of prolonged easing such as the hit to bank profits and dwindling liquidity in the bond market.

"The BOJ said it will achieve 2 percent inflation in two years. But six years have passed" since the implementation of a radical stimulus programme. The policy has provided sufficient benefits to the economy. On the other hand, various side-effects are emerging in areas like financial intermediation and bond market functions. We hope the BOJ takes these into account." Shibato said.