Japan's currency gained 0.8% against the Dollar, trading at 91.61; the highest level since Feb.17. The Yen declined 0.2% against the EUR, to 133.98 per EUR. The Yen's support arises from the fact that it is slowly being replaced by the Dollar as the preferred currency for carry trades.
However, as the Bank of Japan (BOJ) is hesitant about allowing the currency to appreciate without further substantial improvement in the economy, the Yen may have trouble's remaining at such a high level since there isn't much economic foundation behind this rise.
With no major news release from Japan today, the JPY's movements will likely be determined by news from the U.S and Europe.