flying love letters

A princess traped in her own room in a huge castle, has a lovely white bird her as her animal friend, and the library of books that make her feel at ease in rainy days when her friend chu-chan is not around (the bird), and her assistant Ayume and princess Akane (her sister)even though she had those friends around she felt lonely inside most of the time she spends it reading or in the garden with chu-chan . One day she wrote a letter to a unknown person and then she attach the letter with a small rope on chu-chan's leg and send chu-chan away to fly. A young handsome prince was resting in the castle's garden when suddenly a bird landed on his head, with something attached on it's leg. And here the story starts....