So about 80% Girls’ Last Tour, 20% Heavenly Delusion for the first episode. Or something like that.

It’s hard to tell how long is supposed to have passed since the end of civilization in that world. On the one hand, the fact that relatively delicate auxiliary structures like traffic signals are still standing and signage is still legible despite exposure to the weather suggests a gap measured in decades, not centuries (much less Dr. Stone). On the gripping hand, they had a large tree growing out of the center of a building, and I’m pretty sure Hakodate isn’t in the more tropical parts of Japan where trees continue growing year-round. On the third hand, the diner could have been abandoned before the end. On the fourth hand, the original mangaka may not have done the research necessary to realistically depict elapsed time. 🤷

If I had to make a wild-assed guess about the intended timeline, I’d say 20-50 years since whatever-it-was happened. Not terribly long, in other words.