Topside trend line is the latest hurdle
The USDJPY has been trending to the upside in trading today as "risk on" flows send investors out of the "relative safety of the JPY" (that is the Pavlovian reaction).
The 5 minute chart shows the trajectory of the trend today. A lower trend line has done a good job of defining the upward movement. That trend line currently comes around the 109.08 and moving higher. A dipped below the level with more momentum would raise a small red flag for the trend today (it's not the end of the world but with momentum it could weaken the upside a bit).
Taking a broader look at the hourly chart, today the price was able to extend back above its 100 day moving average at 108.728, the 100 hour moving average at 108.80, the 200 hour moving average at 109.00 and now a trend line break at 109.14.
I would expect that traders would use the 200 hour moving average area at 109.00 as a bigger risk defining level intraday. Not only is it "the 200 hour moving average" (a followed risk and bias defining level), and the price has not traded above that moving average since January 22, but it is also the natural support level. A momentum move below that level would be more of a concern for the trend move today and traders will be on alert on a break back below. Holding on the other hand, would still keep the buyers in control.