taken from pantheon.org
The Japanese Shinto sun goddess, ruler of the Plain of Heaven, whose name means 'shining heaven' or 'she who shines in the heavens'. She is the central figure in the Shinto pantheon and the Japanese Imperial family claims descent from her. She is the eldest daughter of Izanagi. She was so bright and radiant that her parents sent her up the Celestial Ladder to heaven, where she has ruled ever since.
When her brother, the storm-god Susanowo, ravaged the earth she retreated to a cave because he was so noisy. She closed the cave with a large boulder. Her disappearance deprived the world of light and life. Demons ruled the earth. The other gods used everything in their power to lure her out, but to no avail. Finally it was Uzume who succeeded. The laughter of the gods when they watched her comical and obscene dances aroused Amaterasu's curiosity. When she emerged from her cave a streak of light escaped (a streak nowadays people call dawn). The goddess then saw her own brilliant reflection in a mirror which Uzume had hung in a nearby tree. When she drew closer for a better look, the gods grabbed her and pulled her out of the cave. She returned to the sky, and brought light back into the world.
Later, she created rice fields, called inada, where she cultivated rice. She also invented the art of weaving with the loom and taught the people how to cultivate wheat and silkworms.
Amaterasu's main sanctuary is Ise-Jingue situated on Ise, on the island of Honshu. This temple is pulled down every twenty years and then rebuild in its original form. In the inner sanctum she is represented by a mirror (her body). She is also called Omikami ("illustrious goddess") and Tensho Daijan (in Sino-Japanese pronunciation).
Relevance to Urusei Yatsura
Amaterasu appears in an manga story in UY volume 11. This story was skipped over during the TV series, but was later picked up and ended up becoming the plot for the final TV show, episode 195.
Aside from that she's referred to during a few dialogues during the course of the series.