Balance of the World ~ The Third Son of the Marquis House, For some reason Reincarnated as a Daughter of the Marquis
Author: Umesugi (梅杉)
A story in which the insensitive main character, who has only loyalty to the prince in his head, grows up as he gets involved in incidents and battles, is loved, and develops friendships.
The daughter of the Marquess, Linaria, remembers her past life when she met the first prince Esmerald when she was 10 years old.
In her previous life, she was not the daughter of a marquis, but her third son, Linalite. As a follower of the First Prince Esmerald, he grew up with him from an early age.
However, when the two were 20 years old, the prince was poisoned by a woman, and his attendant Linalite died shortly afterwards.
She says, "I have to save the life of his highness...!"
Although it is unknown why time has returned and he was reborn as a woman, Linaria decides to live to change the fate of the prince.
Author Twitter link: https://twitter.com/umesugg1
Disclaimer: I do not own this story i'm just a translator