Yuka married Kenji, a junior at her company. Kenji's family consisted of just three people: his father and his older brother. Yuka began her married life living with him. The presence of the cheerful and intelligent Yuka was like a light shining on the dark house of a male household. Her father-in-law cried tears of joy. It seemed as if a happy new life was about to begin, but her reclusive brother-in-law Shuichi gazed at Yuka's beautiful figure and face with a moist gaze. Yuka found Shuichi's attitude creepy, but tried to be cheerful. One day, Yuka was given an aphrodisiac and was raped by Shuichi. Although she was supposed to be filled with taboo and disgust, she was surprised by Shuichi's huge penis, and felt an unprecedented pleasure and sought him out herself. Yuka became immersed in her relationship with her brother-in-law.