It's a great place to retire in my opinion. They are happy to give you a retirement visa if you have half a million in the bank. Japan can be a cheap, high quality, and very respectful place to be if you're a senior.
If the retiree brings his/her own pension, how could this be detrimental? An economy isn't production alone, there have to be consumers, too. Importing affluent retirees is essentially propping up domestic demand.
