In the beginning the universe was made up of chaos and light. Light does not weigh much and so it started to drift to the top of the universe. Chaos is a heavier matter and could not drift very high thus creating heaven and clouds (Takamagahara). Some even heavier chaos stayed at the very bottom of the universe creating Earth and assumably creating man along with it. Immediately after the creation of heaven, clouds, and Earth gods started to rise. The Kotoamatsukami deities being the first then two other gods from which five were born and so on.
The Japanese creation story from which this is paraphrased is Tenchikaibyaku.
Kotoamatsukami ordered Izanagi and Izanami (Gods) to create Japan as a place to hold their wedding. The Gods build two large Palaces upon Japan and mate. They have many children some of which are separate islands of Japan thus creating Japan in its entirety.
The Japanese story from which this is paraphrased is The sun, the Moon, and the Wind.
The Sun, the Moon, and the Wind
Shortly after the completion of Japan Izanami is badly burned after birthing a fire deity and dies. As Izanagi grieves over Izanami's death he draws his sword and beheads the son that had killed his wife. From his tears even more deities are born. Izanagi still longed for Izanami and so travels to the underworld in search of his lost wife making him the protagonist. Towards the end of the story Izanami becomes evil and turns on her husband sending the message that raising the dead in impossible “Enraged, she shouted to him that she would each day strangle one thousand people of Japan. He responded that if she did so, he would each day cause fifteen hundred Japanese people to be born." This explains the fifteen hundred children born each year in Japan and the thousand that die.
This story influences Japanese culture by explaining death and birth, something incredibly hard to grasp.