It started with a doorway.
Long before characters were worrying about XP gain or build efficiency, stories were already exploring a more timeless premise: What happens when someone leaves their world and enters another?
That’s isekai.
And it has been around far longer than most people realize.
The True Roots of Isekai
Isekai, which translates to “another world,” did not emerge from gaming culture. It originated as a distinct storytelling tradition in Japan, long before it became a global pop culture phenomenon. It did not emerge from gaming culture. Its narrative DNA stretches back centuries into myth, folklore, and early fantasy.
Stories about crossing into other realms have always existed in many cultures, but in Japan, this idea developed into a recognizable genre of its own. Tales like Urashima Tarō — about a fisherman who journeys to an undersea kingdom and returns to find time has moved differently — already explored the emotional and existential impact of entering another world.
Modern isekai grew out of this tradition. While Western literature had its own portal fantasies like Alice’s Adventures in Wonderland and The Wizard of Oz, Japan shaped the concept into a repeatable narrative framework centered on transportation, reincarnation, and displacement.
Long before LitRPG introduced stats and system mechanics, Japanese storytelling was already asking:
What happens when someone must live in a world that is not their own?
The Rise of Modern Isekai
Fast forward to the late 20th century, and the concept began to take a more recognizable modern form.
Anime and manga of the 1990s embraced the “transported hero” idea with stories like Fushigi Yûgi and The Vision of Escaflowne, where ordinary protagonists were summoned into fantasy worlds filled with politics, danger, and destiny.
The genre gained even more structure with works like Inuyasha, where the boundary between modern life and mythic past became a recurring passageway.
None of these stories relied on RPG systems. They relied on the emotional and narrative tension of being somewhere you did not belong.
The 2000s and the Explosion
By the early 2000s, isekai had fully matured as a genre.
Series like Spirited Away presented a deeply personal journey into a supernatural world governed by unfamiliar customs and hierarchies. Later, stories such as Re:Zero, Mushoku Tensei, and That Time I Got Reincarnated as a Slime explored reincarnation as a mechanism for entering another reality.
These works focused on transformation rather than mechanics. The central question was not how powerful the protagonist could become, but who they would become when stripped of their old world.
Even when later stories began introducing game-like elements, the transportation itself remained the defining feature.
Where LitRPG Comes In
LitRPG, as a recognizable genre, is comparatively recent. It arose from gaming culture and built stories around visible systems — levels, stats, and structured progression.
But many of the most recognizable LitRPG-adjacent narratives borrowed heavily from isekai’s foundation.
Sword Art Online trapped players inside a game world, combining displacement with mechanics. Overlord followed a gamer transported into the body of his in-game avatar. The Rising of the Shield Hero summoned its protagonist into a world that functioned like an RPG.
In each case, the story begins not with stats, but with transition. The system comes later.
Why This History Matters
Understanding isekai’s longevity reframes how we see today’s trends.
LitRPG may be the dominant flavor of progression fantasy right now, but the emotional engine driving many of these stories is older. The desire to imagine oneself in a new world — free from the constraints of the old — predates the idea of quantifying power through numbers.
Isekai is less concerned with optimization and more concerned with identity. It explores what happens when familiar assumptions vanish and survival depends on learning new rules.
The Genre That Was Already There
Today’s readers may discover these stories through stat-heavy dungeon crawls or system apocalypses, but the foundation remains the same as it was decades — even centuries — ago.
A person leaves one world and enters another. Everything else is variation. LitRPG built a framework of mechanics. Isekai built the doorway.
And that doorway has been open for a very long time.