Would Eating Mermaid Meat Really Grant Immortality? The 800-Year Curse of Japan's 'Yasaburōni' Legend

One of the most terrifying elements in 'Gekijōban Mermaid Island's Secret' might not be the monster that eats people, but rather the concept of 'never dying.' The tragedy experienced by Ichihana and Nihana in the film stems from a desire that humanity has fantasized about for thousands of years: What if eating the flesh of a mysterious creature could allow you to escape death and live forever? In the story, Nihana is on the brink of death, and Ichihana, in an attempt to save her dearest friend, kills a mermaid and feeds its flesh to Nihana. Nihana survives but gains an abnormally long, almost endless life. Fearing one day being left alone, Nihana eventually makes Ichihana eat the mermaid meat as well. What seems like a fantastical setting is actually a legend that has been circulating in Japan for hundreds of years. Japan's most famous legend of 'eating mermaid meat to gain immortality' is the story of Yasaburōni. According to the legend, a girl accidentally ate mermaid meat and remained youthful, while those around her aged and died, eventually living for 800 years. The anime does not confirm that the mermaid island arc is directly based on the Yasaburōni legend, but both stories share an ancient Japanese folklore motif: Does mermaid meat bring eternal life, or is it an endless curse that never ends?