Betrothed to My Sister's Ex is a tV series anime that premiered in summer 2025, produced by LandQ studios.

About the production: the story comes from a light novel, there are 12 episodes of about 24 minutes and its current status is "finished".

Its main genres are drama, fantasy and romance, with themes such as Marriage, Royal Affairs, Female Protagonist and Heterosexual.

On AniList, Betrothed to My Sister's Ex has an average score of 73%, a good score, and appears on 26,898 users' lists.

Marie, the second daughter of a poor baron’s household, is treated like a servant by her parents. Even at Marie’s birthday party, her beautiful elder sister, Anastasia, is the star. Outside, Marie bumps into Count Kyuros Granado, who falls for her at first sight. Yet, due to a misunderstanding, the Count proposes to Anastasia. After a tragic accident, Marie must marry the count instead! (Source: Crunchyroll)

Official synopsis from AniList.