ミレイユ・フォン・アウストリア

A girl who is the oldest princess of the kingdom and is the head of state and the navy.
Her ability to fight is feared by pirates and she has the nickname "Princess of the Blue Sea".
Her parents, the king and her queen, have passed away, so she inherited the throne and is now the queen of the kingdom. She has a serious personality and is strict with himself and others, but only to sister is she sweet and fond of.