A young Japanese-American man arrives at his grandmother's old hometown in Yamaguchi, begins to stay at her family's elite but dysfunctional household, and gets entangled in a sinister plot of murder.
For the study of Japanese culture, American-Japanese young man Robert came from the United States to visit his grandmother's old hometown in Yamaguchi Prefecture. The rich family patriarch Karasawa is the head of a bank. In his luxurious family estate, he has three young daughters: the eldest daughter Reiko, after a minor scandal, has carved an independent life for herself and doesn't live there anymore; second daughter Noriko, whose fiance Fujimura suddenly disappeared before their wedding three years ago, is a mentally and emotionally unstable wreck; and the third daughter Keiko, who's engaged with the local public prosecutor Minegishi, begins to temporarily help Robert in his research work. One morning, all of a sudden, Fujimura returns and reconciles with Noriko. Despite Karasawa's initial apprehension, they get married. Fujimura accepts a job in his father-in-law's bank and they begin to stay in a luxurious house in the same household. Meanwhile, Fujimura's impolite, alcoholic, estranged, troublemaker younger sister Tomoko visits them uninvited and comes to stay with them in the same building. Trouble begins when Noriko begins to have frequent mysterious bouts of illness and Fujimura finds himself in desperate need of a large sum of money. Then, suddenly, while moving books and furniture, Keiko and Robert discover three mysterious undelivered letters written by Fujimura, addressed to Tomoko. Keiko and Robert begin to suspect that the letters are part of a sinister plot to murder Noriko.
