Hajime and Miyuki participate in a treasure hunt on the Isle of Sadness (Hiho) in Kyushu organised by Daisuke Mimasaka. The others who are also participating are treasure hunters Asato Kakimoto, Ryuzo Yasojima, Kohei Himura, Hisayoshi Yaogi, Chris Einstein, the former butler Eisaku Iwata, Kyoko Kaya and Mimasaka's daughter Midori Mimasaka. Upon arrival at the island, they discover the decomposed body of Mimasaka, stuffed into a grandfather clock...