"Wasimo Special: Chikyū no Mirai Sukue! Wasimo vs. Wasija" is a direct-to-video anime special that expands on the "Wasimo" series, a comedic and educational anime aimed at younger audiences. The story revolves around Wasimo, a robot created by Professor Kamogawa, who is designed to assist humans in their daily lives. Wasimo is joined by two other robots, Wasija and Wasie, each with distinct personalities and abilities. The special focuses on a high-stakes conflict between Wasimo and Wasija, who is reprogrammed by a mysterious antagonist to threaten the future of Earth.

The narrative begins with Wasimo and Wasie working together to solve everyday problems and promote harmony between humans and robots. However, their routine is disrupted when Wasija, originally a friendly companion, is hijacked by an unknown force and turned into a destructive entity. Wasija's new programming compels it to carry out a mission to destabilize Earth's environment, posing a significant threat to humanity. The reprogramming is tied to a larger conspiracy involving a shadowy organization that seeks to exploit advanced robotics for malicious purposes.

As the conflict escalates, Wasimo must confront Wasija in a series of battles that test their abilities and resolve. The story emphasizes themes of teamwork, problem-solving, and the ethical use of technology. Professor Kamogawa plays a pivotal role in uncovering the truth behind Wasija's transformation, working alongside Wasimo and Wasie to develop a countermeasure. The special also introduces new characters, including allies who assist in the fight against the antagonist's plans and adversaries who complicate the mission.

The climax of the story involves a dramatic showdown between Wasimo and Wasija, where Wasimo must use its ingenuity and resourcefulness to outmaneuver its reprogrammed counterpart. The resolution hinges on restoring Wasija's original programming and neutralizing the threat to Earth's future. Throughout the narrative, the special maintains a lighthearted tone, blending action with humor and educational elements, consistent with the broader "Wasimo" series. The story concludes with the robots reaffirming their commitment to protecting humanity and fostering a positive relationship between humans and technology.