Misora Arimiya, addressed as "Lady Misora" within the Arimiya Family, serves as the first stepdaughter and biological sister to Chisato Arimiya. Her family comprises deceased stepfather Kamoshige Arimiya, stepmother Sumire Arimiya, and stepsister Shion Arimiya. She possesses chestnut brown hair and dark brown eyes, with her dress color differing across media adaptations.

After Kamoshige's death, Misora held the position of second heiress. Stepmother Sumire, seeking Kamoshige’s hidden inheritance within a safebox, suspected Misora and her sisters knew its altered PIN. Sumire directed family secretary Tatsuya Katori to extract this information through coercion.

In Episode 1, Misora confronts Katori in Arimiya Tower’s hallway. Aware of his father Kadono’s prior blackmail attempt against Kamoshige, she questions whether Katori aims to complete his father’s unfinished business, pulling him into a private room. Katori dismisses her accusations as misunderstandings.

Following Katori’s manipulation and possession by Kamoshige’s spirit, he uncovers the safebox PIN and seizes control of the Arimiya Family. Months later, Misora becomes one of Katori’s sex slaves alongside Sumire and her sisters, enduring recurrent abuse echoing their experiences under Kamoshige.

Tension defines Misora’s relationship with Sumire, punctuated when Misora calls her stepmother a "Bitch."