Princess Pplea, sometimes called Puruah, hails from the kingdom of Yapaya. Her defining trait is an absolute, lifelong inability to laugh, creating a significant emotional challenge within her realm. This condition drives Yapaya's representatives to seek external help, leading them to commission Professor Senbei Norimaki from Penguin Village. Their specific request is for him to build a comedic robot capable of making the princess laugh for the first time. The film's core narrative focuses solely on this mission to overcome Princess Pplea's unique condition through the comedic efforts of Arale Norimaki. Her story concludes when Arale succeeds, finally provoking laughter from Princess Pplea and resolving the central conflict rooted in her initial emotional state.