[jarym]

I would love to know. Most other central banks are raising rates and tightening policy, especially the US which probably affects the Japanese currency the most.

From my naive view, the BoJ can't keep depressing rates without leading to huge currency weakening and consequently the cost of imported goods can create a lot of inflation.

Inflation like that can quickly go out of control so imo it won't be long until they start seeing 10+% or higher like some other places.

[arc-in-space]

Other central banks are other central banks. Their monetary policy does not affect Japan in the same ways the actions of the BoJ do.

Weakening currency is (indirectly) more or less the point. Lack of monetary expansion may very well not be the only reason for their economic stagnation, but it was a hindrance, so this turn is overall very good news; there's certainly a possibility they'll overdo it, but that remains to be seen.