okay I will say this once based upon my headcanon.... she's renko's older sister
I think the problem with that theory is you have to consider the advances made in Mary and Renko's time compared to Sumireko's (roughly our own). Grand Unified Theory has been solved, TORIFUNE has been launched and apparently long abandoned, moon tourism (not cheap apparently), reliance on synthetic strawberries and bamboo shoots, as well as a somewhat dystopian lack of smiles on children (though their world doesn't seem terribly depressing overall). I think an aunt or grandparent would be more realistic.
I think the problem with that theory is you have to consider the advances made in Mary and Renko's time compared to Sumireko's (roughly our own). Grand Unified Theory has been solved, TORIFUNE has been launched and apparently long abandoned, moon tourism (not cheap apparently), reliance on synthetic strawberries and bamboo shoots, as well as a somewhat dystopian lack of smiles on children (though their world doesn't seem terribly depressing overall). I think an aunt or grandparent would be more realistic.
so wait you saying maribel and renko is from year 2080 or so?
so wait you saying maribel and renko is from year 2080 or so?
Possibly. It's certainly not confirmed. Officially, based on those advancements, they're merely from a vague, unspecified near future. But as long as we're speculating I wouldn't expect to see some of those advancements even in 20-30 years, maybe longer. Just a guess. However, I wouldn't want to put a number to it. I just think being her older sister is too soon. Even being old enough to be her mother might be too soon.
With *that* said, I feel there's a hint of social commentary in ZUN's near future setting that is meant to reflect our own world, even if only symbolically.
Of course ZUN could always deviate from this and have his current outside be far more advanced technologically than ours with those happenings only being a stone's throw away. Although based on the Moriya Shrine inhabitants' descriptions and Sumireko's own depiction, among others, I wouldn't expect it.