Nenokuni (Land of the Roots) (根の国)
Nenokuni is the underworld in the Japanese myth. It was expressed as 'Nenokatasukuni' (根堅州國) or 'Sokotsunenokuni' (底根國) in "Kojiki" (The Records of Ancient Matters), 'Nenokuni' (根国) in "Nihonshoki" (Chronicles of Japan), 'Nenokuni sokonokuni' (根の国底の国) or 'Sokonenokuni' (底根の国) in a Shinto prayer.
"Kojiki" explains that the entrance to the Nenokuni was Yomotsu Hirasaka (the slope that leads to Yominokuni, the land of the dead), which was the same entrance to Yomi (also known as Yominokuni) (see the section of a visit to Nenokuni in the article of the myth of Okuninushi [chief god of Izumo in southern Honshu Island, Japan, and the central character in the important cycle of myths set in that region]). It is generally considered that the Nenokuni and the Yominokuni are the same. In the Shinto prayer of purification carried out on the last day of June, however, the Nenokuni is the country beyond the ocean or the bottom of the sea rather than below ground.
Kunio YANAGIDA considered that it has been changed as the Nenokuni locates underground because the word 'Ne' in the Nenokuni was the same as 'Niraikanai,' the belief in the other world handed down in Ryukyu, and expressed as '根' (ne; literally means a root) in Chinese character. In an opinion, originally Takamanohara (plain of high heaven) and the Nenokuni were located in the same level as Ashihara no Nakatsukuni (literally, "Central Land of Reed Plains," which refers to the human world), but Takamanohara was moved to upper so the Nenokuni was considered to be located underground. Anyway, people considered that the Nenokuni was underground, which led it to be identified with the Yominokuni, the land of the dead.
In a Shinto prayer, sin and impurity were washed away to the Nenokuni, and it was considered the root of evil spirits and noxious vapor. On the other hand, "Kojiki" states that Okuninushi brought back a sword, a bow and arrow, and a koto (a zither-like Japanese musical instrument) that would be a basis of regal power from the Nenokuni, while Susano (god in Japanese Mythology) called the Nenokuni 'Haha no kuni' (the Dead Mother Country). From these things, it is considered that the Nenokuni was regarded as a world that had both positive and negative distinctions.
Kunio YANAGIDA claimed that the Nenokuni was originally the land of life and wealth (the root of the country) because the Nenokuni was cognate with 'nirai.'
While some people claimed that it was obvious the Nenokuni was located underground, some have tried to interpret the myth realistically and guess where it was since old days. Under those attempts, some considered that it was in Izumo Province to which Izanami and Susano had close ties. The burial mound which is said where Izanami was buried from ancient times is located in Yasugi City in Shimane Prefecture, which is located between Yonago City in Tottori Prefecture and Higashiizumo Town in Shimane Prefecture, where the place named Yomi is located and where a presumed location of Yomotsuhira-saka is placed, respectively. Because of this, Biten YASUMOTO wrote in his book, 'Yamatai Koku and Izumo Shinwa' (Yamatai Kingdom and Myths of Izumo), that the whole eastern part of Izumo was the Nenokuni.
There is also a view that Kii Province, especially Kumano Sanzan (three major shrines, Kumano-Hongu-Taisha, Kumano-Hayatama-Taisha and Kumano-Nachi-Taisha), which had a close connection with Susano, was the Nenokuni due to the description in the myth that Okuninushi went to 'Kinokuni' (the land of Ki) before he visited the Nenokuni. Kumano has been a holy ground of the other world since ancient times where Izanami was buried according an arufumi (alternative variants) of "Nihonshoki." However, those who support the opinion of Izumo objected that they just associated 'ne' (a root) with 'ki' (a tree).