in the monthly timeframe, I see USDJPY bullish for three months already GBPJPY and EURJPY have similar movement.
A combination of certain criteria or characteristics of currency pairs can help to choose a currency pair for trading.
In general Japanese Yen is the currency of Japan, should JPY pairs have higher volatility in the Asian market session, but in fact not always so, pair like EURJPY, has high volatility in London and New York sessions.
The best time to day trade currency pairs were 2008 to 2009. Any major currencies were great for day trading. now, the Best currency pairs to day trade are NONE. currencies tend to move relatively little. There are many other futures that are much better for day trading. BTC futures is one of the worst futures for day trading due to its horrific bid-offer spread.