This is one of the best fundamental based trades nowadays. The Euro is overbought, Yen is sold heavily (I refer to CFTC Report). It gives the possibility of collapse of demand / supply for these currencies. The United States is going to raise interest rates in the future, which will translate into an increase in market risk in the future. This will be the main factor that will result in the closing of short positions on the japanese Yen and it will increase pressure to sell pairs with the japanese Yen in the background. The Euro is currently not in a certain inflationary situation, especially core is muted. The tone of the European Central Bank's statement is now positive, because the bank does not want the Euro to fall too fast. As investors or traders, we have to be able to predict the future in some sense and try to position ourselves before Mr. Market will notice what is going on.
Remember to invest consicously, pay attention and be aware all the time, have a good Risk:Ratio reward, control your feelings and emotions... and good luck! :)