During Thursday's trading session, the Japanese Yen significantly depreciated against the European Common Currency by 0.86% or 108 pips. Note, that the Yen also depreciated 0.74% against the US Dollar.
The drop was driven by the news that a Japanese bank is intending to buy a German multi-billion-dollar aviation finance business, thus, the demand for the Japanese currency decreased.
In recent months, low liquidity has often caused unexpected rises or rapid falls in major currencies, as markets are calm before the European trade starts.