Living alone with her son, Nami Horikawa spends her days reminiscing about her late husband as she watches her only child grow stronger each day. One day, she finds her eyes drawn to her son's increasingly muscular body—especially his impressive cock—and her long-suppressed desires suddenly erupt. Unable to resist, the mother reaches out and takes his growing shaft into her mouth. As she becomes aroused by her son's hardening manhood, she can't help but crave more of his body. Soon, the forbidden bond between mother and son turns physical, culminating in an illicit sexual relationship. A shocking taboo unfolds within the confines of their home.