Prétear, Volume 1

Himeno is a high school freshman who's having trouble adjusting to the lifestyle of the very rich. Her father Kaoru is a one-time famous author of young girls' novels. One of his greatest fans was Natsue, a wealthy woman who liked Kaoru so much that she snatched him up from the rundown apartment and married him! But Himeno's life is far from rosy. Her dad tends to take the side of Natsue rather than her, and Natsue's two daughters from a previous marriage aren't very fond of their new stepsister.
One day, Himeno takes a shortcut to school and meets a young boy. When she takes the boy's hand, she's transported to a fantasy world that lies on the brink of extinction. And the one person that can stop it is the girl called "Pretear."