The Captain's Sweet Temptation

https://www.cmoa.jp/title/301166/
Failrina, despite being a woman, has risen to become a knight commander. But her life takes a sharp turn: her younger sister steals her fiancé, and in parting, he says to her: “I don’t see you as attractive as a woman.” Devastated, Failrina decides to give up her innocence by attending a masked ball, where she approaches a man she can recognize even through his mask. What begins as a desperate attempt at reclaiming dignity leads to unexpected encounters and romantic complications.