TOKYO -- When the Bank of Japan ended the world's only negative interest policy in March, it emphasized that financial conditions would be kept easy and interest rates would slowly increase.

The yen's weakness stems from the wide rate differential between the U.S. and Japan. (Nikkei montage/Source photos by Akira Kodaka and Yuji Murakami)
Some analysts expect Japan's central bank to use bond yields to stop yen's fall