Due to a mysterious curse Yucie is a 17-year old girl stuck in the body of a 10 year old. Though she has never let it get in the way of living her life she would do anything to become her true age. She lives with a man she calls Father, but in reality he was a warrior who followed what appeared to be a shooting start that led him to baby Yucie, and then devoted his life to caring for her.
On Yucie's 17th birthday she learns of an opportunity to become a chosen "Platina Princess". As part of this competition she is sent to a special school where she learns that there are 4 others under the same mysterious curse, who are all trying to obtain the Tiara. The Tiara has the power to grant a special wish to the Platina Princess once every 1000 years, and all 5 girls dream of becoming an adult for their own reason. Yucie goes for it with clear determination to get the attention of Prince Arc... who is also trying for the Tiara for reasons known only to him.
Based on the synopsis by Mew1Mokuba.