Murasaki Kuhōin is a seven-year-old girl born into the powerful and traditional Kuhōin family, one of the revered Omotegosanke clans. Although officially recorded as the daughter of Renjo Kuhōin and his wife, her biological mother is Renjo's sister, Aoki—an arrangement resulting from the family's strict tradition of pure bloodline preservation through incest, which has weakened their lineage over generations. Like all Kuhōin women, Murasaki was permanently confined to Okunoin, the Inner Sanctuary, a secluded retreat dedicated to breeding and concealing the family's practices. Consequently, she remained unacknowledged in the family registry and received no formal education in her early years.

Her mother, Souju Kuhōin, lived in humiliation and confinement within the Inner Sanctuary until she took her own life due to the intolerable conditions. Before dying, Souju entrusted her only friend, Benika Juzawa—the chief maid of the Inner Sanctuary—with a final wish for Murasaki. On Murasaki's seventh birthday, Benika asked the girl what she desired most; Murasaki replied that she wanted to experience love. Honoring Souju's plea, Benika helped Murasaki escape the estate and placed her under the care of Shinkurō Kurenai, a dispute mediator.

Initially, Murasaki displayed stubborn and snobbish tendencies, shaped by an upbringing where she perceived others as servants and luxury as her due. Unfamiliar with ordinary life—such as residing in a small apartment or eating modest meals—she struggled to adapt. Under Shinkurō's guidance, she gradually acclimated to a simpler lifestyle, learning to appreciate small pleasures like a new mattress or a visit to the public bath. Her curiosity and sincerity led her to ask frank questions about the world, though her lack of common knowledge sometimes resulted in misunderstandings.

Murasaki grew deeply attached to Shinkurō, referring to him as her "interactive sweetheart" and expressing a wish to marry him despite her youth. She exhibited jealousy when other girls approached him and demonstrated a protective instinct toward him. Notable traits included her honesty—she could not lie to anyone who treated her seriously—and a sharp intuition for detecting falsehoods in others. Over time, she formed friendships with other residents in Shinkurō's apartment building, though her conversations occasionally touched on topics too mature for her age.

After being kidnapped and returned to the Inner Sanctuary by her half-brother and family subordinates, Murasaki faced the same oppressive fate as her mother. In a confrontation with Shinkurō, she confessed her true desire not to remain confined. This led to her rescue and subsequent negotiations, during which Murasaki agreed to stay within the Kuhōin mansion only on the condition that the family traditions be reformed. The changes included abolishing the oppressive practices of the Inner Sanctuary, granting her the right to choose her own partner, and allowing her the freedom to lead a self-determined life, including attending school.

In later developments, Murasaki begins attending school as a first-grader, marking a significant step toward integrating into ordinary society. Her relationship with her father, Renjo, evolves as he agrees to her terms and works to change the family's ways out of love for her. Despite ongoing challenges within the Kuhōin family, Murasaki's determination and the support of those around her enable her to pursue a future where she can freely experience love and freedom.