[citation needed] Yume Yume*Yu Yu is loosely based upon the Shinto miko and shrines, as well as four constellations in the Chinese zodiac: Suzaku — The Vermilion Bird of the South (who represents the summer season and Yin,), Seiryuu — The Azure Dragon of the East (who represents the spring season as well as Yang), Genbu — The Black Tortoise of the North (who represents the winter season), and Byakko — The White Tiger of the West (who represents the fall season, Bai Hu in China).
The Azure Dragon of the East, or Seiryuu, shares that he is not happy a human of the Light world has become Miko, and tries to destroy Yume.
The goal of Yume and Rekka is to find the Unicorn and take it back to its home, as it is its own portal between worlds.
Aoi, a boy at Yume's school, is soon revealed to be the King of the Eastern Skies of the Light world.
Discovering this, the team decides they must find all the Guardians of the light world to help the Unicorn.