Himeno Awayuki wants a normal, happy life. But when her nutty father marries a wealthy executive, Himeno finds herself living on a estate the size of a small country and saddles with two stepsisters who won't give her the time of day!

Himeno's life soon takes a turn for the worse when the Princess of Disaster escapes from the realm of Leafenia. The dark princess is seeding the land with demon larva and intends to suck all the Leafe, the life force of all beings, from the world! Lead by the brooding Hayate, seven Knights of Leafe search for the only person who can stop this catastrophe: the Pretear, a special girl who, when merged with a knight, transforms into an all-powerful defender of life. And the Pretear just happens to be Himeno!