The mystery adventure "Izumi Jiken File" series is a mystery adventure game that "deduces the culprit" based on the situation at the crime scene and the information collected by interviewing. The main character, "Izumi Kido", is a female editor in charge of the popular novelist "Kagamitsuki Masamune". After chasing Kagamizuki, who abandoned the manuscript and went on a journey, Izumi arrived in Shonan, the western part of Kanagawa Prefecture. When Izumi finds Kagamizuki and comes on him, Kagamizuki tells with a mysterious face. " Actually, there was a murder case." The victim was a 54-year-old company officer, the scene of the incident was under the breakwater of the port, and the cause of death was a head laceration due to a fall. From the situation at the scene, it looks like an unfortunate accident, but Kagamizuki seems to be convinced that it is a murder. Taizumi, who took the manuscript, went to the city of Shonan to unravel the truth of the incident.