As momentum of JPY and GBP both appear to be directed to the upside and strong, it would feel quite certain to take a short position on GJ wjhen JPY clearly takes the lead on chart of currency strength indices.
However CAD & USD collective selling pressure is lurking and may unexpectedly overpower JPY buying power in the strongest triangle of world economies and cause the three USD, JPY & CAD to flash crash. Then GJ will suddenly turn from a Long to a (fast and big) Short.
Both JPY and CAD send this effect onwards to their respective pairs and trading them should add extra care monitoring the three majors for a possible crash anytime soon.