The events in this follow-up take place four years after those of the initial series. filled with the same wacky creatures, Papuwa-kun, an enigmatic boy, resides on a recently-discovered tropical island. He embarks on absurd escapades alongside his attendant, Liquid, and his amnesiac pal "Rotarou," attempting to circumvent detection by the formidable Ganma Army, Special Corps, and even the Shinsengumi in order to safeguard Rotarou's true identity.