JPY IS expected to weaken, but so is USD.
Most countries that follows USD will feel that JPY is getting more expensive at times.
You really can't compare much this days.
USDJPY went up to IIRC, 145. Now its down to 130〜.
I was lucky to have bought it at a high before going to JP for my previous trip.
I'm not an expert, I just got lucky and gambled while doing research that JPY will reach the peak last September. After which it slowly strengthened back up to 130 in December.
My country follows USD very closely, so when USD falls, it falls too, hence it feels like its back to normal as of now.
I'm heading to Thailand soon, and the rates seems to follow as well. THB was cheaper sometime back in December, as of now it feels like it is strengtening even though its just USD tanking.
Maybe tanking isnt the proper word to use here...
Anyways, JPY and USD are both slowly weakening.
Depends on where you are from, it might be a good or a bad thing.