Japan's Yen soared to an 18-month height on Friday as analysts expect the Bank of Japan to hold off easing policy further for the time being, after keeping interest rates unchanged this week, hammering the local stock index and buoying the currency.

Yen hit an 18-month peak at 110.07, before last trading at 107.16, up a strong 0.87% on the day, while the dollar index, which measures the U.S. currency's performance against a basket of rivals tumbled another 0.51% to trade at 93.26.

Oil prices on the other hand expanded their gains, with Brent crude futures up 13 cents, or 0.25% at $47.89 a barrel, while U.S. West Texas Intermediate (WTI) crude futures added 20 cents, or 0.40% to hover around $46.22 a barrel.

Investors wait for an array of data later today, with the Eurozone's CPI flash estimate expected to show a 0.1% y/y drop in April, compared to March's no-change reading, which would be negative for the common currency.

From the U.S., personal income is forecast to have risen 0.3% m/m in March, adding to February's 0.2% rise, which could prop up the battered dollar before the weekend.