GBPJPY is in a strong support zone on the monthly and weekly charts. More than likely, it may shoot up. I would wait for it to pass 141.077, pull back, then look to buy on the pull back. So far, GBPJPY has not been able to break major resistance zones, which is a huge sign of trend continuation (in this case a downtrend). If it fails to break, and drops, you're looking at a possible 70-100 pip drop again to 138.672 before it rebounds. In that case, have your buy limits placed.
AS of now, GBPJPY is in a tough and sticky part. If you didn't get your trade yesterday (aug 23,2017), don't put a trade in now. Wait it out until you get a clear confirmation.