While celebrating with her friends in her new cheaply rented apartment on the thirteenth floor of a building, the young Sayaka unexpectedly jumps off the balcony committing suicide. Her mother goes insane and her older sister, Mariko, decides to investigate the mysterious death of her sister. She finds that there have been many suicides of young women living in apartment 1303. She finds a book telling the tragic story of the Yukiyo and her mother, the first tenants of the apartment, and uncovers the truth behind the suicides.