(This above is for EU manufacturing, not Japan, but it illustrates it well enough).
Accepting the devaluation would only make it worse as they are 100% energy-dependent, and buy that energy in USD.
That would only increase production costs to their manufacturing, making them less competitive.
That would only mount on top of the other 5-10 cost advantages China already has over them for example.
Keep in mind that prices of energy and raw materials were already going higher globally recently on their own.
They need to de-dollarize their energy and some commodity imports, only then can they afford this kind of weak yen.
And truly get bigger current account surpluses from domestic tourism and more exports it brings.
However, they probably won't have the guts to do this move until shit really hits the fan later.
They can't increase interest rates to revalue the yen as they have a 263% public debt-to-GDP ratio,
They can only send their tremendous UST reserves, sell that to USD, and then to yen, to prop it up.
But the best move is just to de-dollarize energy imports and keep those advantages of the weaker yen.
Then they print yen and pay with that I don't have doubts that many energy-producing countries would accept it.
There are many things that you could actually buy from Japan in return for that yen and safeguard its value in gold or JGBs.
That's why this is more interesting from the US perspective, they are in a lose-lose situation here.
Either allow Japan to start dumping their USTs, in such a moment when the US needs to sell them the most,
Or allow further de-dollarization globally. Both moves from Japan could have ripple effects globally.
Something out of those 2 would need to happen, but I predict much later when Japan is under more serious fire.
Imagine if allies/vassals like these need to start dumping US dollars and their denominated assets, what do other neutral countries think/do?
The US can always disallow Japan to do anything and let them collapse, as they are under their occupation, but it needs it as a launchpad against China.
If Japan starts collapsing like this now, then China would just take their industries, which is maybe an even bigger loss.
And I don't think will fundamentally change until the US starts massively cutting interest rates, which is unlikely ever again.
Also, there are other complications from the depreciated yen, also in the labor sector. Imagine now when it reaches 200-220.