Hangekai
"Hangekai" (繁華界?) was the original dimension that split long before humans populated it. Hangekai remains the same, whereas the mirror dimension which was spawned by the splitting was additionally split into "Heaven", "Hell", and the "Human" world. Both Hangekai and the mirror dimension where Ueki originates are on equal footing of development and characteristics. But the "Human" world's 1 year equals to 100 years of Hangekai, which means earth spins fully around the sun equals to one year but Hangekai is 100 years. And it also means some parts of Hangekai are 100 years advanced than the "Human" world.
The currency of Hangekai is Roude (R). One Roude is equivalent to one Yen.
Read more about this topic: The Law Of Ueki Plus