Basically, it's a book written in a diary format about a girl named Dashti, who is the poor, humble maid of a sort of princess, Lady Saren, who was sentenced by her father to 7 years in a tower, because she refused to marry the man her father told her to. So the lady and her maid are imprisoned together. Luckily there's plenty of food in the tower, so at least they won't starve for 7 years (although they do have rats) and Dashti knows how to write, so she keeps a record of their time in that prison.
About a month of being locked in the tower, Saren's real love, Tegus, visits them, but Saren doesn't want to talk to him because she's scared, so she orders Dashti to pretend she's her. Dashti is quite reluctant to do that, but she does as she's told, and soon she and Tegus become really good friends, him thinking that she's Lady Saren. After a few visits in a row, though, he leaves and doesn't return for the longest time.
With many days, weeks and months skipped, eventually Dashti and Saren manage to escape the tower after nearly 3 years of imprisonment (I won't tell you how they escaped. ^_~). But the world around them has changed a lot. What used to be Saren's home is burned to the ground, so they have to go somewhere else. Dashti decides to take them to Tegus's realm, because she knows they'll be safe there. They get there, but Saren is a bit crazy from years in the tower, and she doesn't want to tell anyone that she's really a Lady, so she works with Dashti in the kitchen scrubbing pots all day.
I won't tell you how, but soon Dashti meets Tegus himself, and they become friends again, him never knowing that she was the one he'd spoken to in the tower. This is when Dashti realizes that she's in love with Tegus, not Saren. He never even met the real Saren, so that means he loves her.
As you can see, it was a really romantic story, and I loved it a lot. ^_^ I don't know why I haven't picked it up before now, but I'm glad I did. I highly recommend it.