Sumire Arimiya, widow of the deceased and corrupt politician Kamoshige Arimiya, endured years of rape, physical abuse, and molestation alongside other women during her marriage. Following her husband's death, she ascended to head the Arimiya family. Her primary goal became accessing a hidden inheritance locked within her late husband's safe box, its passcode changed shortly before his demise.

Physically, Sumire possesses long black hair, black or gray eyes, and notably large breasts. She is typically depicted in a white dress revealing her chest and legs, often shown smoking cigarettes.

Believing her stepdaughters—Misora, Chisato, and Shion Arimiya—might possess the new passcode, Sumire enlisted Tatsuya Katori, Kamoshige's former secretary, to extract the information. She commanded Katori to rape her stepdaughters, but specifically instructed him to secure their willing submission rather than use overt force. This plan stemmed from her desire to claim the inheritance for herself, fueled by jealousy towards her stepdaughters' potential claims and a readiness for manipulation. Although the stepdaughters address her as "Mother," tensions exist, particularly Misora's open hostility.

After Katori accessed Kamoshige's memories while possessed by his spirit and discovered the passcode, he reported it to Sumire. When offered a reward, Katori demanded her sexual submission. Frightened by his resemblance to her abusive late husband, Sumire attempted to flee but was overpowered. Katori asserted he knew she had enjoyed Kamoshige's abuse. Despite her initial pleas to stop, she eventually responded sexually during the encounter and later initiated further contact with him.

Months later, Katori succeeded Kamoshige as family head, earning the title "The Second Coming of Kamoshige." Sumire and her stepdaughters became his sex slaves, subjected to ongoing rape, abuse, and molestation, repeating the cycle of victimization. Her name, meaning "violet (flower)" in Japanese, contrasts with her actions and fate.