Twenty years after leaving home, the second son and his wife return to their family home, warmly welcomed by the eldest son and his wife, the third son, and his fiancée beneath the soft glow of the hearth. The eldest son's wife, Sachiko, was the second son Ken's high school classmate—and the woman he once idolized, now married to his older brother. Meanwhile, Ken's wife, Yoshie, finds herself drawn with intense desire toward the eldest son, Umekichi. That night's events spiral into a chain of encounters that will irrevocably alter the lives of these siblings and their spouses. Directed by Katsuya Ichihara, this is a deeply erotic drama of forbidden emotions and incestuous passion. Torn between family bonds and raw impulse, they cross new boundaries into uncharted desire.