Episode 222: And There Were No Mermaids (The Murder)
Scenario: Conan, along with Heiji, Ran, and Kazuha travel the Isle of Mermaids looking for Saori Kadowaki, who had sent a letter to Heiji asking him to save her from being killed by a mermaid. They try to look for her but find out that she had been reported missing. The group decides to talk with Saori's childhood friends: Toshimi, Naoko, and Kimie, the island elder Mikoto's great-granddaughter. They also meet Rokuro Fukuyama, the fisherman who is Toshimi's fiancé. Every year on Isle of Mermaids, a festival is held where 3 people win the Dungong Arrow that is said to give immortality to its carrier. Kimie gives Ran and Kazuha each a ticket for the lottery to win a Dugong Arrow since a couple had cancelled and promised to take them to Saori's house after the festival. During the festival, Kazuha wins an arrow, which she receives along with Naoko and Saori's father Benzo. The festival is brought to a disastrous end when Toshimi is found dead, hanging from the waterfall.
An investigation follows but neither Conan nor Heiji can say if it's a murder, suicide, or accident until an autopsy is performed. Naoko suggests that Toshimi could be looking for the Mermaid's grave, then explains how an actual mermaid was found in a burning warehouse. At Toshimi's funeral, Naoko herself is strangled to death, her corpse hung out on the beach net, and her Dugong Arrow stolen.