One day, a girl who was raised as a boy has her entire life flipped upside down... A nameless boy who dreams of, becoming a knight works as a servant for the renowned Romagnolo Family. One day when he is seventeen years old, the boy faces his first monthly period and his mother tells him that actually, he is a girl. She is Count Romagnolo's Illegitimate child and her mother secretly raised her as a boy to protect her. When the count finds about his illegitimate child, be decides to use her as a pawn to protect his daughter, Maylene, from an unfavorable engagement. In that instant, the child who has lived for seventeen years without a name is given one, and her fife begins to change drastically. Her name is “Nullitas” which means nothing.