Masanao Ikeda

In 1946, on a fictional island called Gokumon-tou, located in the Inner Sea of Seto, the famous detective Kindaichi intended to pass his convalescence after the invitation of his war buddy Kitou Chimata, the successor son of the powerful clan of the Kitou Family. But Kindaichi arrives alone, bringing the bad news of Chimata's death. However, the truth is that Kindaichi is not on the island to recover. Before Chimata died, she uttered the words: "My sisters will be killed!" Indeed, as the three sisters are murdered one by one in horrible and strange ways, Kindaichi desperately tries to find the culprit and in the process discovers the intrigues of the family, secrets, island mentality, discrimination, and eccentricities, With the backdrop of the turbulent postwar period.

Six high school tennis clubmates, including railroad investigator Noriko Hanamura, are going on a day trip to Kawaguchi Lake. However, one of them, Ayako Hirayama, does not show up even after the arranged time for the meet-up has passed. Magazine writer Yumi Tachiki, who planned the trip, calls Ayako but gets no answer, so Noriko and the others, believing Ayako will catch up with them, proceed to their destination. Even though Yumi and Noriko call Ayako many times, she does not answer. Yumi receives an urgent work request after arriving at Tenjozan Park by ropeway, so Noriko and the others return to Tokyo leaving Yumi at the mountain. None of them had any contact with Ayako the entire day. That night, Noriko receives a call from the Yamanashi Prefectural Police informing her that Yumi's body has been found stabbed in Tenjozan Park. One of the ropeway employees happened to witness a mysterious woman wearing a hat and a mask following Yumi down the mountain trail that evening...