Lady Oborozukiyo is the younger sister of Kokiden, the powerful consort of Emperor Kiritsubo and mother of Crown Prince Suzaku. Her father, the Minister of the Right, anchors her within a politically formidable family, placing her firmly in the faction opposing Genji.

Genji first encounters her after a court event, finding her door unsecured. He slips into her chamber and rapes her, declaring his dominance: "It will do you no good. I am always allowed my way. Just be quiet, if you will, please." During this violation, she retains a measure of agency by concealing her identity. Genji later coins her poetic sobriquet, "the lady of the misty moon" (Oborozukiyo), inspired by the imagery on a fan she gave him.

Their clandestine affair continues intermittently after Genji learns her true identity at another gathering hosted by her father. This liaison becomes politically volatile following Kokiden's elevation of Oborozukiyo's rank and her placement at court for the now-Emperor Suzaku. Discovery by the Minister of the Right, finding Oborozukiyo and Genji together, directly triggers Genji's pivotal exile to Suma.

Despite his banishment, Oborozukiyo sustains contact through exchanged letters. Upon Genji's return, their sexual relationship ceases, a decision attributed to her. Nevertheless, she remains emotionally preoccupied with him. Emperor Suzaku explicitly notes this fixation, warning her of the political consequences should she bear Genji's child: such a child would be deemed a commoner, diminishing her standing and influence at court, underscoring the tension between her personal longing and political reality.