A Tale of an Unknown Country(2002)

Shiranai Kuni no Monogatari

16 year-old Princess Rosemary is furious with her older brother Prince Mash. Without her consent, he has promised her hand in marriage to Prince Lionel of Yurinera. Although the two kingdoms are neighboring courntires, they are worlds apart. Arudera is a small, poor country, but is filled with an abundance of greenery and untouched nature. It stays in existence from Prince Mash's tourism initiative (in which he gives personal tours of his country and castle for a fee) and Princess Rosemary's baked goods which she sells in the garden. Yurinera is a very large and wealthy country.

Princess Rosemary decides to disguise herself and journey to Yurinera to sabotage the marriage proposal and sneak a peek of her husband to be. But when she arrives she discovers Prince Lionel to be completely different from the cruel and cold-hearted person he is rumored to be. Despite her original plan, she finds herself falling in love with him!

(Source: CMX)