USDJPY pair is heavily controlled by the Japanese Central Bank (JCB).
JCB constantly intervenes in the market to weaken or strengthen Yen (JPY) according to their requirements.
Whenever there is a monetary policy statement scheduled by JCB, just assume that USDJPY will move big time.
Now it is not necessary that USDJPY will move everytime but most of the time it does move.
Read this blog post in which I describe in detail a USDJPY swing trade that lasted 2 days and made 600 pips with a 10 pip SL.
Always make sure you use pending orders when opening and closing a trade.
Use a very small stop loss.
If the pending order doesn't gets filled, don't worry.
There are trades a plenty.
You will get another trade pretty soon.