While Conan tries to prove that a corpse found deep in the woods was the victim of more than just a hunting accident, the Detective Boys gains a new member: a curious bear cub! Then Detective Mouri's office is graced by a very traditional lady with very traditional and very deadly sword skills. And at a place called Mermaid Island, a woman is found hanged under a waterfall. It seems the legendary mermaid's curse has struck again...unless Conan and Hattori Heiji can find an all-too-human culprit!