Judging from widening gaps in interest rates between Japan and other countries, the yen could possibly head to around 115 to the dollar this summer.

A key downside factor for the dollar earlier this month was a seasonal pickup in demand for the yen toward the close of the business year.

After having recovered the 110 yen level in February, the dollar fell below 105 yen in mid-March, prompting the Bank of Japan to step in.