Realm of Twilight/Demon's Realm?

Connections

• Hattori pursued the Demon Kagima, getting lost at sea until a stork lord showed her the passages between the twilight and the night to here, where she found a bizarre world of talking stones and eight-armed ferrymen.
• Jiro was secreted away and trained as a child here

Context

I had a hard time finding anything in Japanese mythology or beliefs that seemed remotely similar to the demon/twilight realm. The current assumption is that they're the same place, since Hattori's lore states that it was located between the twilight and the night. If they are indeed different, appropriate adjustments will be made here.

Searching for "eight-armed ferrymen" and "talking stones" has also come up empty so far, except for the fact that most Japanese yokai (demons, spirits, and supernatural creatures) were known to shape-shift. Also, there are a couple of yokai legends that tell of boulders possessed by despondent or vengeful spirits, which would cause some of these rocks to wail and cry loudly at night.