Upon the fifth day, the creator would bring a gift to Gaia, one that neither Apollo nor Sol would have ever expected. Gaia would be given the power to bring forth life. True sentient life.
And through the instructions given to her, Gaia would then bring forth mankind. With the first woman and the first man. Sol found this new breed of creature, these mortals fascinating. Apollo on the other hand was jealous and very against the idea of giving Gaia such an immense responsibility. When brought to Amaterasu's attention, the creator would simply reply with-
"The choice was preordained, just like you now being here; was known to happen."
After this Gaia would begin with the humans, and then afterward would create animals for them to befriend, ally with, and also utilize to help them grow their civilization. Unfortunately, during the first 500 years of humanity's existence, one human would attempt to eat meat for the first time and would find it enjoyable. Going against the initial want of companionship that Gaia had wanted. Breaking her heart.