Itsuwari no Freja

Freya is a timid yet athletically daring girl who lives in Tena, a small village nestled within the kingdom of Tyr. Beaming with kindness, Freya is beloved by the people of the settlement, while the bravery of her close childhood friends—Aaron the "Black Knight of Tyr" and his younger brother Aleksi—make them proud village heroes. As the two brothers have been serving the kingdom's Crown Prince Edvard at the capital for the past three years, their sudden reappearance is an emotional reunion for the three friends. However, the celebration is cut short when the brothers tell their adoptive mother, Freya's birth mother Skadi, that they are preparing to defend against Sigurd—a neighboring empire threatening war if Tena is not surrendered. Tensions soon intensify when Freya overhears that Prince Edvard is dying and that Sigurd is willing to take Aaron's head instead if Tyr refuses to give Tena over, prompting her to run to the kingdom's Rokka Castle to warn her beloved friend. But instead of finding him, she encounters an individual who bears a striking resemblance to her and quickly gives Freya a dying wish—to protect Tyr by taking his place as Prince Edvard. [Written by MAL Rewrite]