It seems so, although canonically it's not. At least the human characters are supposed to age, but that makes us see most of the protagonists (except for Youmu, maybe?) in the middle of thelr 20s. Unless Reimu and Marisa were beating up scary monsters before they were 8 or something.
There's a hundred ways to immortality in the place just laying around and the whole land is some kind of wacky magic space/time anomaly. Everyone that isn't suppose to be ageless might be anyways just for the merit of living there.
Now that I think about it this pic reminds me of Houtou and Koumei from Shin Koihime Musou. Two cute bookworm lolis who liked to read ero books, like post #408417.
TheMonsterHunter said: Akyuu is way older than that. She has countless memories from her other eight lives.
Well that current incarnation is 18. If we count previous Incarnations then you're right.
Waaah... H-hey, Akyuu, is this really okay? Can you really put that there? ...Foreign books really are wonderful...The shadow of impropriety approaches!Hyaaa!♡ Look, Kosuzu! Isn't what they're doing incredible?! Isn't it?!