Quoting one short part of an article out of context

Usual disclaimers about western papers writing about Japan.

"Gradually but relentlessly, Japan is evolving into a type of society whose contours and workings have only been contemplated in science fiction," Eberstadt wrote last year. With a vast army of older people and an ever-dwindling younger generation, Japan may become a "pioneer people" where individuals who never marry exist in significant numbers, he said.

Except that except for one Stross novel and a Ringo novel I am hard pressed to name an example of this sort of scenario in SF from outside Japan. Non-catastrophic population decline seems to be a blind spot for many SF writers, probably because it's not dramatic enough.

To whichever cat it was

I can feed myself but thanks for the mouse.

Attack on Titan

Doesn't seem entirely upbeat.