How Old Is Rimuru Tempest in Code Geass?

The question of "how old is Rimuru Tempest in Code Geass" is a fascinating one, sparking curiosity among fans who love to imagine crossovers between their favorite anime universes. However, to set the record straight right from the start, it's important to clarify a key piece of information: Rimuru Tempest, the beloved protagonist from That Time I Got Reincarnated as a Slime, is not actually a character in the Code Geass series.
While it's fun to speculate about such epic encounters, Rimuru's incredible journey and distinct age progression belong entirely to his own richly developed world, the Jura Tempest Federation. Our goal here is to give you the definitive answers about Rimuru's age within his actual universe, That Time I Got Reincarnated as a Slime, and help you explore every facet of his existence.

The Truth About Rimuru Tempest: A Star from Another Story

Rimuru Tempest burst onto the scene as the central figure of That Time I Got Reincarnated as a Slime (Tensei shitara Slime Datta Ken), not the world of Britannian empires and Geass powers. He began his extraordinary life as a human salaryman named Satoru Mikami before his untimely death and subsequent reincarnation as a humble, yet incredibly powerful, slime monster. This transformation is the cornerstone of his entire narrative, setting him on a path to become a benevolent ruler and one of the most compelling figures in modern anime.
If you're interested in understanding why this particular crossover question might arise, or just want to confirm the origins of both series, we have a dedicated guide for . This will help clarify any confusion and direct you to the correct lore for both universes.

Unpacking Rimuru's Age: More Than Just a Number

Determining Rimuru's age isn't as straightforward as counting birthdays. His unique circumstances mean we look at his lifespan in two distinct phases: his human life and his existence as a slime. Both contribute to the wisdom and experience he embodies, even in his seemingly youthful form.

His Life Before Reincarnation

Before he became the iconic blue slime, Rimuru Tempest lived a full life as a human named Satoru Mikami. At the time of his death, which set in motion his reincarnation, Satoru was 37 years old. This human lifespan is crucial, as it established his foundational personality—his politeness, his work ethic, and his strong sense of justice—all of which carry over into his new existence. His human experiences shape his mature decision-making and empathetic leadership style.
To truly appreciate the depth of his character, you might want to dive deeper into and see how those years influence his subsequent actions and development.

The Slime Years: A New Lease on Life

After his reincarnation, Rimuru's age calculation becomes a bit more fluid. While physically he doesn't age in the traditional sense as a slime, his time spent in his monster form adds to his overall lived experience. Including the years he has spent as a slime, his total age comes to 39 years. This two-year period, though short, is packed with immense growth, evolution, and the acquisition of god-like powers. It's during these "slime years" that he rapidly evolves from a basic slime into a formidable force capable of founding a nation and commanding respect across entire continents.
For a comprehensive breakdown of his evolution and the significant events during this period, you can find more details in our guide .

Beyond Years: How Age Shapes Rimuru's Character and Leadership

Rimuru's combined age of 39, encompassing both his human and slime lives, deeply influences his multifaceted personality and his extraordinary leadership. He possesses the maturity and thoughtfulness of a seasoned adult, inherited from Satoru Mikami, which makes him a wise and diplomatic leader. Yet, he also retains a youthful, fun-loving side, often remarking that he'll "always be a child at heart." This unique blend allows him to make careful, strategic decisions while also connecting with his diverse subjects on a personal level.
His experiences foster an inner cunning and shrewd nature, enabling him to navigate complex political landscapes and survive against powerful enemies. Despite his immense power, his past anxieties and his ingrained polite nature often make him humble, sometimes even to his own detriment in negotiations. However, his core kindness and unwavering loyalty to those he cares about are always at the forefront. Exploring offers further insights into the complexities of this beloved character.

A Hypothetical Crossover: What If Rimuru Met Code Geass?

While Rimuru Tempest doesn't exist within the Code Geass universe, the allure of imagining such a crossover is undeniable. What if a being of Rimuru's power and strategic acumen were to suddenly appear in the world of Britannia, Geass users, and Knightmares? Would his diplomatic nature lead him to try and mediate the global conflicts? Or would his protectiveness over his allies align him with Lelouch's rebellion, or perhaps even an entirely new faction?
Such a scenario opens up fascinating possibilities for how his unique skills—like Great Sage's analysis, Predator's absorption, or his myriad of elemental and magical abilities—would clash or combine with the technological and supernatural elements of Code Geass. Could his nation-building experience offer a different path than Lelouch's radical revolution? For those who enjoy speculative fiction and pitting powerful characters against new challenges, we invite you to explore . It's a fun thought experiment, even if purely fictional.
In the end, while Rimuru Tempest may not be part of the Code Geass narrative, his own story in That Time I Got Reincarnated as a Slime offers a rich tapestry of adventure, growth, and compelling character development that continues to captivate audiences worldwide.