Amaterasu was the eldest of three, fraternal triplets. As the eldest she took her role as leader quite serioiusly. Susanoo felt that she took it far too seriously, and he wanted to be given an equal share of authority. Izanagi, their father, grew quite irritated and banished him.
"Amaterasu, I just wanted to say goodbye."
"No, you didn't. You want to make me feel bad that father banished you!"
"That's not true! And I'll prove it to you. Let's have a contest. We shall make new gods using the others vessels." Susanoo declared.
"Okay. You can use my necklace, and I will use your sword."
Using these divine tools, Amaterasu created three new goddesses from the Heavenly Blade, while Susanoo made five new gods from the Grand Jewel.
"You see, I told you that I genuinely wanted to say goodbye. My five to your three proves that I am sincere."
"It proves nothing! It was my necklace. You're lucky I let you use it but the five are mine and the three are yours because they are from your sword." Amaterasu smirked.
"You are such an idiot!" Susanoo screamed throwing things and yelling in his anger. Animals flew and plants were knocked down as he vented his rage. He even threw a pony at her loom. It was when Mimiso lost her head that Amaterasu began to cry.
She ran to a cave to hide, and the world was plunged into darkness. Winter and darkness had come to the world.
'How shall we get her to come out again,' the kami wondered. 'We cannot allow this to continue.' They each tried talking to her in turn but she just blocked the door and cried louder.
In the end, it was decided that singing and dancing with some festive lights might do the trick. Amaterasu slowly came to the entrance and peeked out. Seeing the glitter of her tiara in the mirror, she slowly peeked out. The kami opened the door, and Amaterasu emerged, her light reentering the world. Winter ended and slowly spring and summer returned.
Amaterasu apologized for her reaction to the incident, and Susanoo was banished.
That's the last time I babysit triplets!