Mika Yamaguchi, a widow raising her son alone, has recently noticed her growing son beginning to see her not just as a mother but as a woman again. One day, she agrees to let her son's friend stay over for the night in the absence of his own mother. Yielding to the young man's persistent advances, their relationship crosses the line into forbidden territory. Mika's body, still radiating the allure of her youth, can no longer resist the nightly visits from her son's friend. Desperate to keep the affair a secret from her son, she surrenders to escalating desires, falling deeper into a taboo passion.