Koji was disturbed by the moans of his mother, Yuri, leaking from his parents' bedroom. He had noticed that his parents were planning to have a child. From his son's perspective, this might be something to celebrate. However, when he learned that Yuri had a sordid side he had never experienced, uncontrollable emotions welled up within Koji. It was jealousy towards his father and the desire to possess all of Yuri. When these emotions reached their limit, Koji's twisted affection for Yuri would cross the forbidden line.
