During her husband's overseas assignment, Rika finds herself sexually unfulfilled, enduring each day in a state of pent-up desire. With her sister-in-law away for work, she visits her real brother's house to help with household chores. There, she meets her adorable nephew, and though hesitant at first, she begins using him as an outlet for her overwhelming sexual urges. What starts as a secret quickly spirals into an illicit, incestuous relationship that pushes the boundaries of morality.