Sharaku and Wato set out to look into a mysterious old ship, and their investigation soon pulls them into a sea voyage that takes them around a string of strange islands. The story draws on the Easter Island sea voyage arc of Osamu Tezuka's manga The Three-Eyed Boy Comes Here, and Tezuka supplied the original story and an animation outline. Toei Animation made this 1985 special as the eighth entry in an animated series for a 24-hour broadcast, taking over from Tezuka Productions. The production put entertainment ahead of theme, mixing adventure, comedy and supernatural elements.