When Izanagi fled from his wife in the Land of Hades, after trying to get her to come back to him, he knew he was unclean. So, he went to the river to purify himself in water. (This was a Shaman custom.) Izanagi removed his clothes, from which many gods were born as he threw them down. (These gods were named using the ancient language of Japan. The names were later changed to suit the demands of the new language, which developed in later times. This is convenient for writers.)
A total of 14 gods were born as he did this. Then he found the best place in the river, where the speed of the current was just right, to bathe himself. As he bathed, many other gods were born. They were born at the bottom of the river, in the middle of the river, and at the surface of the river. Then the greatest wonder of all happened! When he washed his face, Amaterasu, the Sun Goddess was born from his left eye, Tsukiyomi, the Moon God, was born from his right eye, and Susanoo, the God of Storms and the Seas, was born from his nose!
生まれた神の数は全部で十四人にのぼりました。 伊耶那岐は、川の中で水を浴びるのにちょうどよい流れの場所を見つけます。 伊耶那岐が体を洗っているうちにも、川の底で、真中で、表面で多くの神が生まれ出ました。最も偉大な奇跡が起こったのです。 伊耶那岐が顔を洗うと、左の目から太陽の神・天照が、右の目からは月の神・月読が、鼻からは嵐と海の神・須佐之男が誕生しました。
The last three children were the most important to him, and the only ones he regarded as his own, probably because they came from his body! Therefore, they were the natural rulers of the great land, which would become Japan. (This story of the birth of the Sun and the Moon is repeated in Chinese and Philip-pino mythology! Susanoo is unique to Japan.) As Izanagi’s three children, Amaterasu, Tsukiyomi, and Susanoo grew to be adults, Izanagi gave his daughter, Amaterasu, his necklace of curved jewels. (I really believe the curved jewels are fertility symbols.) He also gave her control of the Sun and the Day. To Tsukiyomi, he gave control of the Moon and the Night. To his last son, Susanoo, he gave control of Storms and the Seas.
Later, we will see that Susanoo never took over his first kingdom, but chose to be the ruler of the Land of Darkness, as Izumo no Kuni was called at that time.