On the fourth day, she would create the moon and sun, her last finishing upon the surroundings of Earth. The sun breathed pure fire and plasma, as the moon's gaze gave birth to the concept of night itself, with the sun creating the day.
With these two would come the goddesses Apollo and Sol. The two would be of a natural duality, being the archetypes of the dark and light. The two would be at constant war over what the other had. Apollo wished to rule over the day and all creatures who lived in and relied on it, and vice versa for Sol, who wanted the night. Both sides were at eternal odds no matter what their creator did to subdue their conflict. Eventually, Amaterasu came up with a grand idea to bring the two together: to create their younger sibling, Gaia, ruler of life, the earth, and eventually the sustainer and bringer of life itself.
Gaia in her youngest moments was innocent and oblivious, though now she is still very oblivious, but her innocence has long since turned into wisdom. Apollo and Sol, while still very much against one another, would stave off their war against the other in order to spare Gaia and her luscious world. At least for now.