The former territory of the Japanese islands seemed to have shrunk by more than a third compared to thousands of years ago, due to the melting of the Arctic and Antarctic ice caps causing sea levels to rise, and the bullet-sized landmass of former Japan was inundated by a third.
Like the Chinese, the Japanese also possess some traditional cultures, and having a strong attachment to one's homeland was a major feature, so the majority of those living on the former Japanese islands were of Japanese descent, and the current Federal Councillors also resided here.
Perhaps because of the low population and the overly rapid economic development, Yusuf Zuck could tell that the standard of living here was very high.
When Yusuf Zuck arrived, many Earth Immortals had already gathered on the island, ranging from First Level to Twelfth Level, and more were still arriving.