The Japanese Yen soared against its US counterpart after the Bank of Japan decided to stand pat, taking the USD/JPY pair sharply lower to a multi-month low level. The major plummeted to its lowest level since August 2014 and dropped below 104.00 handle to trade at the session low level.Given the uncertainty surrounding the 'Brexit' referendum in UK on June 23, the Japanese central bank decided to leave its annual asset-purchase target unchanged at 80 trillion Yen and its deposit rate steady at negative 0.1%. The central bank raised concerns that a vote to move out of the European Union would trigger turmoil across global financial markets and would negate the effect of BoJ's decision to announce additional stimulus measures. This, over and above Fed's decision to leave its benchmark interest rates unchanged on Wednesday and jittery equity markets across the globe are also the factors supporting sharp appreciating of the Japanese currency.Traders now look forward to today's releases of the US CPI report and weekly jobless claims data to get some respite from the recent sharp slide for the USD?JPY pair.Technical levels to watchFrom current levels, the pair seems vulnerable to continue drifting lower towards its next major support near 103.00 round figure mark. Meanwhile on the upside, attempts of recovery above 104.00 handle is likely to confront immediate resistance at 104.30 level. Even if the pair manages to clear this immediate resistance, any further recovery now seems to be capped at an important handle break-point turned strong resistance around 105.00 region.