Magic Knight Rayearth is an animation series featuring three 14-year-old girls who are transported to the magical world of Cephiro by the Princess Emeraude where they must embark on a quest to save the kingdom from the evil tyranny of Zagatos.

Princess Emeraude is the "pillar" of Cephiro. Her prayers can effect the entire world of Cephiro. In a certain way, Cephiro is a reflection of Princess Emeraude's heart. When Emeraude falls in love with Zagatos, she is unable to concentrate on her prayers anymore and the result is a Cephiro in chaos, overrun by monsters and wars. Her age is thought to be quite old, but she always appears to be a little girl.