The Japanese word “isekai” can be interpreted as “bizarre world” in English as described by Lefler in ReelRundown. For this justification, several people categorize isekai as a subgenre of fantasy; its central supposition involves a protagonist’s journey from one world to another.
An article from Rice explains that Urashima Taro is credited with pioneering the core idea of isekai, which he subsequently incorporated into Japanese folk tales. While the term “isekai” (verbatim “entangled in another world”) is a modern concept, the genre it describes has existed for quite some period. Furthermore, this has progressively gained popularity across a broad spectrum of individuals and cultural contexts due to its ties to a wide variety of global religious faiths and mythologies that have long been dedicated to enthusiasm by many.

The Evolution of Isekai
Countless people throughout the world have revered mythological writings for centuries. This may be related to the genre’s massive popularity, as the reader is more likely to become invested in a story if the world the author creates is one with which they are unfamiliar. In addition, the audience is situated in a comparable position as the protagonists, as they generate insights into the setting through the identical tests and perspectives that shape the protagonists. It is worth mentioning that this particular subgenre gained traction in Asia when the pandemic struck.
The concept of a protagonist trapped in a varied world is as old as literature. However, the form in which such stories are told has evolved over the centuries, with isekai representing the most recent iteration.
From Don’t Stop Thinking’s historical analysis, the development of the “trapped in another world” can be broken down into five-time frames: the mythological era, the legendary era, the discovery era, the modern era, and the isekai era.

- The Mythological Era
Within the context of the myth of Persephone, she was kidnapped and taken to the underworld. This is comparable to the myth from Japan in which Izanagi travels to the underworld in quest of his wife so that he can bring her back to the realm of the living. Most of the time, the protagonists are deities themselves.
- The Legendary Era
To share tales in this era, authors have shifted their focus from Gods to valorous sentient creatures divided by oceans rather than being cast away to another world. The story of Odysseus’s travels is a perfect illustration of this proposition.
- The Discovery Era
During this period, trifling mortals could achieve authority sufficient to dominate the world they were trapped in, highlighting how human beings could assume the characteristics of a god through their actions and influence.
- The Modern Era
The famous Mark Twain book, A Connecticut Yankee in King Artuhur’s Court, is the progenitor of the modern isekai genre, incorporating features from earlier periods.
- The Isekai Era
In this period, the lead characters are social outcasts and average citizens of the new world who eventually rise to prominence there. At this moment, when things are still shaping up, experts believe the genre has only a remote chance of becoming widely popular in the West. However, since everything cannot be anticipated with certainty and Japan relishes a massively excessive media influence, there is always a chance that this could be false.

The First Isekai
The origins of the isekai genre remain a topic of debate among fans; while many theories exist about what could be the first isekai, we will be basing our answers on RETORO’s YouTube video entitled “My Search for the First Isekai.”
In the video, Retoro answers that the Isekai genre of anime and manga traces back all the way to the birth of anime in the 1960s. One could argue that the first examples of Isekai can be found in Sally the Witch; it’s about a young princess of magic, Sally, who accidentally transports herself to Earth and struggles to navigate this new world.
While the earliest example of a potential isekai is found in the 10-minute short film “Izakaya No Ichiya” from 1936, the animated film follows a poor man who visits an izakaya restaurant and is transported to a world under the sea, where he experiences fantastical scenes. However, at the end of the film, it is revealed that the entire experience is likely just a drunken dream.
Other anime, such as Majokko Megu-chan and Mahōtsukai Chappy, also feature protagonists transported to unfamiliar worlds. However, it wasn’t until Aura Battler Dunbine in the 1980s that the genre truly began to take shape. The protagonist, Sho Zama, falls down a well and finds himself in another world. This anime clearly checks all the boxes for the current definition of Isekai.

But what about manga? One possibility for the first Isekai manga is Crest of the Royal Family, which features time travel and sees protagonist Carol subjected to an Egyptian mummy curse where Carol is brought to ancient Egypt. Another contender is Fushigi Yuugi, which sees protagonist Miaka Yuki transported to a different world after opening a mysterious book in a library. This world is clearly different from her own, and Miyaka faces many dangers in her attempts to navigate it.
The definition of Isekai can be subjective and unclear at times. Some may argue that time travel should be excluded from the definition, while others may argue that if the character ends up in an unknown world that is unfamiliar to them, it still qualifies as isekai. Regardless of how one defines the genre, it’s interesting to trace its origins and speculate about its beginnings. Trying to pinpoint the exact origin of isekai can be challenging, but exploring its development over time can provide insight into how it has become one of the most popular and beloved genres in anime and manga.

The Popularity of Isekai
According to a YouTube video by Garnt or “Gigguk,” the Isekai genre has gained popularity in recent years in the anime world. In the past, fantasy anime shows featured the main character transported to a different world rooted in traditional fantasy with inspiration from Western fairytales, such as Alice in Wonderland, which has influenced other works like The Wizard of Oz and The Chronicles of Narnia. These classic stories laid the foundation for the genre and influenced global media. Alice in Wonderland even received an anime adaptation in 1983, which resembled some of the themes and tones of modern isekai shows.
In the 90s, well known anime like Escaflowne, Magic Knight Rayearth, and Inuyasha featured the main character transported to a different world, but they were not like the isekai shows we know today. These shows were an extension of the many fantasy anime shows that came out in the 90s and were rooted in traditional fantasy with inspiration from old Japanese or Western folklore. Moreover, during that time, female protagonists were common, and the isekai genre was not considered separate from other fantasy anime shows. The shows featuring female protagonists were not seen as their own genre with the same tropes and cliches. Instead, they were viewed as an extension of the numerous fantasy anime shows that were released in the 90s.
As the fantasy trend started to die out in the 2000s, the elements that we now expect from an isekai became prevalent in the genre. The idea of having your conscience trapped in a virtual world was introduced in the Greed Island arc of Hunter x Hunter, while harem elements were added in Zero no Tsukaima in 2006.

Sword Art Online (SAO) had a massive impact on the anime industry as it filled a niche for popular anime targeted toward gamers at a time when there wasn’t much competition. Its success marked the point where the genre we now know as isekai found its footing. Compared to the previously mentioned shows from the 90s, SAO had a massive shift in the way the concept was approached. It featured a male protagonist who was more powerful than everyone around him and had an entourage of love interests. It was also set in a world that was not traditional fantasy.
Isekai offers more relatable main characters than traditional fantasy, which is one of its best aspects. Having a character from our world navigate and learn about a new world allows the audience to share their experience and learn about the world with them. The story tends to favor gradual progression and world-building, so exposition is provided early on. The isekai genre is a definitive platform that thrives on self-insert characters, making it one of the truest forms of escapism, particularly for its wide audience.
The isekai genre has become a common source of material for anime in the last decade. There are now hundreds of different light novels from different authors. Large publishers for light novels are now having to actively restrict the creation of young male characters trapped in fantasy worlds. For example, Kodansha Entertainment’s “Novels that Adults Want to Read” contest banned stories containing a teenage protagonist in any form of isekai. If even Kodansha had to put their foot down about the overabundance of isekai, it’s clear that this concept has grown beyond what anyone could have expected. Moreover, the sheer volume of new isekai stories coming out suggests that it won’t be slowing down anytime soon.

2023: The Year of Isekai
Due mainly to the success of manga, manhwa, and manhua adaptations, this genre of storytelling is currently on the upswing. In fact, over 15 titles in the isekai genre are scheduled for release in the coming year, including highly anticipated works such as “Reborn as a Vending Machine” and “Summoned to Another World… Again?”
Thus, the Isekai genre has expanded and developed significantly over time, making it a remarkable success despite its long history.
Read more: Summoned to Another World… Again?! Anime Reveals 2nd Promo Video and Key Visual