No one said the weak yen made Japan more attractive. It's just that the difference between economies is such that the weak yen isn't as much of a factor. E.g., it appears Vietnam's dong has depreciated (though not as severely as the yen). And the Chinese economy isn't what it used to be.
Obv ppl still feel it's both a good economic deal or a chance at better opportunities or they wouldn't be coming...
https://en.vneconomy.vn/vietnams-currency-woes-battling-depreciation-amid-global-economic-headwinds.htm