The rising 200 hour MA
The same disclaimer is in place for the USDJPY as the EURUSD (and all currency pairs). That is if you have some shopping to do, shop. The markets have little economiic news and traders to get things going. So be aware.
But if you must, what level would be the potential technical level of the day, I would earmark the rising 200 hour MA. Last week, the price corrected toward the level and found support buyers. The pair also tested the 38.2% retracement at 109.223 and the swing low from the Friday after the UK election (on December 13). Those levels would be targets on a break of the 200 hour MA now.
The high on Friday and today, was able to extend above the 100 hour MA (blue line - high reached 109.532), but could not sustain momentum. That has given the sellers more control.