Fiene, a count's daughter, has been coldly neglected by her own family. Unknown to them, she leads a double life as the legendary and most powerful witch in the kingdom, known as the Witch of Dawn. When she enters a political marriage with Sion, the handsome future duke and a prodigious ice mage—the youngest ever to be named one of the Five Sages—he coldly declares, “I will never love you.” Fiene is secretly relieved, hoping for a hands-off arrangement that leaves her free to pursue her own goals. However, she soon discovers that the person Sion is actually in love with is the Witch of Dawn—her own disguised identity. The story unfolds as a romantic comedy of misunderstandings, with a relentlessly optimistic and cheerful noble lady and a socially awkward, outwardly frigid mage whose true feelings are directed at his own wife’s alter ego.

The setting is a fantasy kingdom where magic and noble politics intertwine. Fiene’s motivation stems from her desire for freedom and purpose beyond her oppressive family; her magical identity allows her to operate independently. Sion, though brilliant and powerful, struggles to express his emotions and harbors an unrequited love for the witch who saved his life four years prior, unaware she is his new bride. Supporting characters include an ancient great sage referred to as “Ghost-san,” who exists in a state where others cannot perceive him and serves as a mentor figure. The narrative arcs include the initial political marriage and the couple’s awkward cohabitation, Fiene’s covert activities as the Witch of Dawn (such as infiltrating a villain’s mansion), and the escalating tension as Sion’s admiration for the witch clashes with his distant behavior toward his wife. The series balances lighthearted comedy with sincere emotional moments as the two slowly close the gap between their public personas and private truths.