Tenson Koorin (てんそんこうりん)
(Two Pictures of Tanson Koorin)
“Tenson Koorin” means that Ninigino Mikoto (ににぎのみこと), who is among the Heavenly Gods, came down to Ashiharano Nakatsukuni (あしはらのなかつくに), the Earthly World, to rule the world. Ninigi is one of the two sons of Ameno Oshihomimino Mikoto (あめのおしほみみのみこと), who is among the sons of Amaterasu (あまてらす). Ninigi’s mother’s name is Yorozuhata Toyoakitsushihimeno Mikoto (よろずはたとよあきつしひめのみこと), who is a daughter of Takami Musuhino Kami (たかみむすひのかみ).
Originally Amaterasu planned to have Ameno Oshihomimino Mikoto rule Ashiharano Nakatsukuni, but Oshihomimi became a father of Ninigi while waiting for his dispatch to Ashiharano Nakatsukuni. Now Oshihomimi suggested his mother that she send Ninigi to the Earthly World instead of him.
Now Amaterasu decided to send Ninigi, who is her grandson, to the Earthly World to have him rule there.
When he was about to go down to Ashiharano Nakatsukuni, Ninigi noticed that there was a god at the place called Ameno Yachimata (あめのやちまた), who is showing the way to Takamagahara (たかまがはら) and the way to Ashiharano Nakatsukuni at the same time.
Amaterasu and Takamimusuhi asked Amenouzumeno Kami (あめのうずめのかみ) to ask the god who he was. Ameno Uzumeno Kami is the one who danced marvelously when Amaterasu hid herself in Ameno Iwato (あめのいわと). Later on, she was going to be an ancestor of the clan which would produce dancers for ceremonial occasions at the Inperial Palace.
The god adressed himself as Sarutabikono Kami (さるたびこのかみ) and introduced himself to Ameno Uzumeno Kami. Karutabiko said that he was trying to help Ninigi so he would be able to go down to the Earthly World with no problem.
So, Sarutabiko guided Ninigi with his followers – Amenokoyaneno Mikoto (あめのこやねのみこと), Futotamano Mikoto (ふとたまのみこと), Ameno Uzumeno Mikoto, Ishikoridomeno Mikoto (いしこりどめのみこと), and Tamano Oyano Mikoto (たまのおやのみこと). They are called “Itsu Tomono O (いつとものお)” and they were to be the leaders of their professional groups from then on.
Amaterasu, Ninigi’s grandmother, gave him three important sacred items only for the Heavenly Gods to possess – Yasakano Magatama (やさかのまがたま) and Yata Kagami (やたかがみ), and Kusanaginoturugi (くさなぎのつるぎ).
“Magatama40” by Jnn. Licensed under CC BY 2.1 jp via ウィキメディア・コモンズ – https://commons.wikimedia.org/wiki/File:Magatama40.JPG#/media/File:Magatama40.JPG
Officially they are called “Sanshuno Jingi/Imperial Regalia of Japan (さんしゅのじんぎ). Especially, Amaterasu told Ninigi and Omoikaneno Kami (おもいかねのかみ), his follower god, that they should think of Yata Kagami as her soul and that Omoikaneno Kami should be in charge of taking good care of it from then on.
(Tenson Koorin Myth in Kojiki)
This is how Tenson Koorin happened. Now Ninigi starts his reign in Ashiharano Nakatsukuni, supported by his follower gods from Takamagahara.