Born into a noble family renowned for its magical prowess, Tilia is the only member without any magical power. Branded as useless by her family, she is treated as little more than a servant and endures constant contempt and abuse. Her only solace is a childhood friend, but even that hope is shattered when her stepsister steals him away, forcing Tilia to flee her home. Alone in the capital, she is rescued from a dangerous situation by Duke Alvis, a powerful noble known as the Beast Knight because of his bond with mythical creatures called divine beasts. To Tilia's surprise, gentle divine beasts such as unicorns and pegasi are inexplicably drawn to her, a phenomenon that captures Alvis's attention. Suspecting that she possesses a rare and valuable ability, he offers her a position as his exclusive maid. As Tilia begins to live and work in the duke's estate, she slowly discovers that her supposed uselessness masks a genuine talent: she is a rare wielder of holy magic, a sacred attribute that resonates with divine beasts. Her growing bond with Alvis, who harbors an obsessive love for mythical creatures, deepens into mutual affection, but their path is complicated by lingering family ties, a manipulative stepsister, a former fiancé who refuses to let go, and the pressures of noble society. Over time, Tilia learns to embrace her true worth and finds both freedom and happiness through her unique power and the connections she builds.