Futuroman, identified as Miraiman, operates as a space-time coordinator from the future. His core duty is monitoring and correcting disruptions across timelines. He detects a critical anomaly: monsters from multiple timelines have merged into one reality, creating an imminent threat to Earth.

Miraiman travels to the present, arriving at the Nohara household. As Misae Nohara prepares cup ramen, the scent distracts him. He accidentally materializes near a Sirimarudashi doll, compromising his mission's secrecy. He explains the crisis to the family: monstrous entities are converging, and failure to defeat them within strict three-minute intervals in the future will catastrophically damage their present reality.

To combat this threat, Miraiman uses the Sirimarudashi doll as a conduit to grant the Nohara family temporary superhero transformations. These powers enable them to confront the monsters. However, Hiroshi and Misae become excessively engrossed in their superhero roles, neglecting daily responsibilities and exhibiting symptoms akin to addiction. Their prolonged absences fighting in the other world lead to tangible repercussions; a powerful monster's battle inflicts real-world collateral damage, injuring the Nohara parents.

Miraiman possesses abilities including interdimensional travel through hanging scrolls and energy-based powers enabling the transformation of others. His dependence on the Sirimarudashi doll as a vessel limits his direct intervention. His distinct personality features a fixation with cup ramen, which initially jeopardizes his mission but also humanizes his otherwise bureaucratic role as a temporal regulator.

Following the primary monster threat's defeat through a unified effort by the Nohara family and allies like Action Mask, Miraiman facilitates the restoration of spacetime stability. He subsequently departs, ensuring the family returns to their normal lives without further disruption.