"When Izanagi, the Lord who Invites, turned his back upon the unclean place, and bade farewell to Yomi, the World of the Dead, whither he had journeyed upon a quest, he beheld once more the Land of Fresh Rice Ears, and was glad. And he rested by the side of a clear river that he might perform purification.
And Izanagi-no-Mikoto bathed in the upper reach. But he said, "The water of the upper reach is too rapid." Then he bathed in the lower reach; but he said, "The water of the lower reach is too sluggish." So he went down for the third time and bathed in the middle reach of the river. And as the water dropped from his beautiful countenance there were created three sublime deities - Ama Terassu, the Glory of High Heaven; Tsuki-Yomi-no-Kami, the Moon-Night-Possessor; and Susa, the Impetuous, the Lord of the Sea."
If you are a follower of the Naruto manga, and are current with the latest chapters, you will no doubt find that the names are very similar to the names of the techniques born out of the Uchiha clan's Sharingan.
Ama Terassu - Amaterasu (Itachi and Sasuke)
Tsuki-Yomi - Tsukiyomi (Itachi and Sasuke)
Susa (Susano) - Susano'o (Itachi and Sasuke)
Izanagi - Izanagi (Danzo)
*Select the space between the brackets to read the names - and be warned... they might be spoilers! :)
Tsukiyomi from the anime
Amaterasu from the manga
In fact, the story of Izanagi and the birth of Amaterasu and the other two gods is part of a very old legend in Japanese Shinto culture. It is believed that the Emperor of Japan is a descendent of the goddess Tsuki-Yomi, who sends her grandson down to earth to pacify the land of Japan.
Naruto draws more than the names of these techniques from Japanese mythology. In the legend, it is said that Amaterasu is born from the left eye of Izanagi, and Tsuki-Yomi from his right. Compare this with the story of the Mangekyou Sharingan, where the user creates the black flames of Amaterasu from his left eye, and manipulated space and time using Tsukiyomi, with his right.
One of the more prominent features that manifests itself is the "Sword of Kusanagi", a legendary sword, and one of the three Imperial Regalia of Japan. It is shown to be weilded by both Orochimaru and Sasuke. According to the legend, Susano finds the sword in one of the tails of the eight-headed demon-serpent called the Yamata no Orochi, which he kills to save his bride. The eight-headed serpent that comes out during the Sasuke-Itachi fight, and Itachi using his Susano'o to defeat it makes the scene almost a portrayal of historical drama.
The eight-headed serpent of legend, slain by Susano.
Orochimaru's Hydra Technique, slain by Itachi's Susano'o technique.
References of this sort abound, and it only needs knowledge of Japan's culture to recognize them and understand their significance.