In the sense that it's in between one's final destinations of either a heavenly or infernal afterlife (inasmuch as they're "final" at all...) then the Sanzu no Kawa and Higan istelf correlate with Limbo.
In the sense of it being a final destination that isn't heaven, some form of Hell (jigoku), or direct reincarnation back to Earth, then you also have plenty of relatively neutral options, including the netherworld where Hakugyoukuro resides (and you can meet up with Yuyuko and Youmu).
In the sense that it's in between one's final destinations of either a heavenly or infernal afterlife (inasmuch as they're "final" at all...) then the Sanzu no Kawa and Higan istelf correlate with Limbo.
In the sense of it being a final destination that isn't heaven, some form of Hell (jigoku), or direct reincarnation back to Earth, then you also have plenty of relatively neutral options, including the netherworld where Hakugyoukuro resides (and you can meet up with Yuyuko and Youmu).
Living with Yuyuko and Youmu isn't so bad at least for our poor kid.
In the sense that it's in between one's final destinations of either a heavenly or infernal afterlife (inasmuch as they're "final" at all...) then the Sanzu no Kawa and Higan istelf correlate with Limbo.
In the sense of it being a final destination that isn't heaven, some form of Hell (jigoku), or direct reincarnation back to Earth, then you also have plenty of relatively neutral options, including the netherworld where Hakugyoukuro resides (and you can meet up with Yuyuko and Youmu).
Come to think about it - the whole Gensokyo can be considered as limbo and being these two variants at same time. Supernatural entities, mythos, beliefs and as of recent even urban legends are (re)incarnated in here with them either to vanish, to thrive or to resurge. Everyone with developed enough background have this. Quick examples: Mokou can't die, lives close to her immortal nemesis and remainder of her past (her immortality orgins part); Yuyuko being death incarnate and being almost literally chained to her grave which is in turn being the chain that keep even more vicious death incarnate.
There's can be more, but I'm not feeling like to search for it more. Hope you get what I mean.
Not to mention, children don't usually have the money to pay the fee to travel the Sanzu River to reach anywhere. They're generally stuck there, at the side of the river. I can't remember the reference, but apparently Komachi can sometimes be found playing with those children.