In the Creation of the World within part of the Gaia, one of the first primordial gods Kunitokotachi and Amenominakanushi summoned two divine beings into existence, the male Izanagi and the female Izanami, and charged them with creating the first land. To help them do this, Izanagi and Izanami were given a spear decorated with jewels, named Amenonuhoko (heavenly spear). The two deities then went to the bridge between heaven and earth, Ame-no-ukihashi ("floating bridge of heaven"), and churned the sea below with the spear. When drops of salty water fell from the spear, Onogoro was created. They descended from the bridge of heaven and made their home on the island.
Izanami helped stir the oceans on the Bridge of the Heavens, and settled down with Izanagi on Earth during the year 60,000,000 BCE, along with other gods such as Zeus, Odin, El, Brahma, among others, with the pair of twin gods settling in the east, more specifically in the region where present-day Japan is located, on their island.
Eventually they wished to be wed, so they built a pillar called Ame-no-mihashira ("pillar of heaven") and around it they built a palace called Yahiro-dono. Izanagi and Izanami circled the pillar in opposite directions and, when they met on the other side, Izanami spoke first in greeting. Izanagi did not think that this was proper, but they mated anyhow. They had two children, Hiruko ("leech-child"), who later came to be known in Shintoism as the god Ebisu, and Awashima, but they were born deformed and were not considered deities.
They put the children into a boat and set them out to sea, then petitioned the other gods for an answer as to what they did wrong. They were told that the male deity should have spoken first in greeting during the marriage ceremony. So Izanagi and Izanami went around the pillar again, this time Izanagi speaking first when they met, and their marriage was finally successful.
The two gods lived for thousands of years on Earth, but then she gave birth to Hi-no-Kagutsuchi, the Deity of Fire, and died from the severe burns of the flames. Izanagi was so angry at the death of his wife that he killed the newborn child, thereby creating dozens of deities. She was then buried on Mt. Hiba, at the border of the old provinces of Izumo and Hōki, near modern-day Yasugi of Shimane Prefecture.
When she perished, she went to Yomi, the Land of the Dead, a place similar to Hell, filled with of pain and suffering. Izanami ate from the furnace of Hell, as a result, the Goddess was trapped in Shinto Hell. She went to petition the deities of the Netherworld to let her go.
When Izanagi went to get his wife, she made her husband promise not to look at her, while she was occupied. However, while Izanami was sleeping, Izanagi disobeyed by taking the comb that bound his long hair and set it alight as a torch. Under the sudden burst of light, Izanagi was greeted by the sight of the horrid form of the once beautiful and graceful Izanami with the Eight Thunders protruding from her body. She was now a rotting corpse of flesh with maggots and foul creatures running over her ravaged body. Crying out loud, the scared Izanagi could no longer control his fear which caused his death-ridden wife to wake up.
He was scared by his wife's appearance and left Yomi. Ashamed by Izanagi's indiscretion, she sent the Yomotsu-Shikomes, the Thunders and Yomotsu-Ikusas after him. Izanagi sealed the entrance to Yomi with a boulder. After that day, Izanami cursed the Earth, vowing to kill 1,000 living beings every day, with Izanagi responding to his wife's threat by saying that every day he would create 1,500 more living beings, and thus their marriage was over. She became the Yomotsugami, the Goddess of the Land of the Dead.
Even though there was a time Izanagi's apology was enough to calm the goddess's heart and calm her mind, but deep in her unconscious, due to years of stored grudge and hate, all that stored hate of the goddess couldn't accept forgiveness and love. that had sprouted in the goddess's heart again. She had hated Izanagi so much that when she forgave him the hatred was already solid and practically palpable, it had literally become a new entity.
Just as in the beginning of creation, when the light illuminated the darkness, this made the darkness angry and moved away as much as possible from the light, the darkness of Izanami's hate did not accept the light that came from the heart of the goddess and if away from her, with Izanami expelling all her negative aspects that personified into an entity called Amatsu-Mikaboshi, the king of chaos and evil, Izanami's shadow. The creature tried to attack the goddess Izanami and the god Izanagi, but with the two of them together they managed to expel Izanami's shadow from the Shinto pantheon and Earth, sending him into space.
This was the tragic love of Izanami and Izanagi with their first child Kagutsuchi always kept her company and was extremely loyal to his mother, Izanami, usually abiding her every whim. This is in stark contrast to his thoughts on his father Izanagi who he has a disdain for, not just for killing but for leaving Izanami in Yomi.
"Mother! Calm down!" A handsome young man with long hair and muscular frame that had characteristics of flames violent spewing from around his body as he tried calm down a woman whose body seem rotting and having several open wounds with maggots and insects crawling in them, giving her a corpse-like appearance, with eight thunders coming out of her body, giving her a hideous and frightening appearance.
The young man was Kagutsuchi, the first child of Izanami and who often comforted his mother while the woman was Izanami who had violent grief and sent waves of miasmic energy within the land of Yomi.
"I told him not to look!! Why!! Why!! Why!! Why!!!"
She screamed violently while her son winced in pain affected by her power but kept his composure and helped ease the pain of his mother by being there. Izanami caused calamities within Japan as death seemed to spike and kept killing innocents from her broken heart. It was pitiful to see the woman grief that the person she loves most abandoned her even after seeking forgiveness she was unable to let go of her deep hatred.
"Child, Stand aside." A voice came and Kagutsuchi felt a primordial presence and soon a gust of wind came in the form of a Divine bird and immediately recognized who it was.
"Auntie!" It was none other than Amihan who used her authority to suppress the power of Izanami while inducing her to calm down. Kagutsuchi finally felt assured that his mother would calm down then noticed someone with her.
"Who are you?" He felt a powerful divinity coming from the person who looked regal and stoic, seemingly stunned. The person had a handsome face and perfect build along with long black hair reaching his chin wearing what seemed to be an overcoat.
The most frightening thing is that he could feel something more dreadful than death coming from him. He is unsure what his intentions are but he needed to protect his mother even from him. Kagutsuchi immediately stopped when his aunt Amihan stopped him and said.
"No need to fret, child. That man is my consort." Kagutsuchi was taken aback hearing his Aunt when he recalled that even after countless years she hadn't found someone to call a consort yet this man before him was her consort and made him speechless. The person turned towards him, allowing Kagutsuchi to see his face much closer and see his smiled and said.
"Guess I'll be your uncle, Kid! Call me Ryuu." He was still a bit shocked that this man was his uncle but seeing his welcoming smile and charisma made him easily trust him and said.
"I'm Kagutsuchi, god of fire." After introducing himself, Izanami began to break through Amihan's divinity, overwhelming it with her own. Even though Amihan and Izanami were both Primordial gods, the former hardly worshiped and was not comparable to a former Creation god and completely shattered the authority.
Izanami looked at her with killing intent and attacked Amihan only to stop when she saw Ryuu who was looking at her without any disgust, only pity since he was the god of Depravity, Flesh and other grotesque things that her appearance is tame compared to his. She then runned toward Ryuu who remained unmoving and saw her leap for an embrace surprising Kagutsuchi and Amihan before hearing Izanami speak.
"H-Husband you've changed."