The way I see it, no it doesn't have 2 realms, but then I also don't see the Yin Yang that way either, so it could well be down to the way you view life etc.
Reiki is not a dualistic practice, there is no light, there is no dark, there just is, which is also the way I see the Yin Yang.
It will be interesting to see what other think :-}}
Namaste
Rob
Truth is not a property of language because language has not been able to express abstract ideas as efficiently as concrete items