Isekai

Isekai (Japanese: 異世界, transl. 'different world', 'another world', or 'other world') is a sub-genre of fiction. It includes novels, light novels, films, manga, webtoons, anime, and video games that revolve around a displaced person or people who are transported to and have to survive in another world such as a fantasy world, game world, or parallel universe with or without the possibility of returning to their original world. Isekai is one of the most popular genres of anime, and isekai stories share many common tropes – for example, a powerful protagonist who is able to beat most people in the other world by fighting. This plot device emphasizes worldbuilding and non-protagonist characters, and typically allows the audience to learn about the new world at the same pace as the protagonist over the course of their quest or lifetime. If the main characters are transported to a game-like world, the genre can overlap with LitRPG.
The concept of isekai started in Japanese folktales, such as Urashima Tarō. However, the first modern isekai works were Haruka Takachiho's novel Warrior from Another World and Yoshiyuki Tomino's television series Aura Battler Dunbine.
The concept of isekai has antecedents in ancient Japanese literature, particularly the story of a fisherman Urashima Tarō, who saves a turtle and is brought to a wondrous undersea kingdom. After spending what he believed to be four to five days there, Urashima returns to his home village only to find himself 300 years in the future. Other precursors to isekai include portal fantasy stories from English literature, notably the novels Alice's Adventures in Wonderland (1865), A Connecticut Yankee in King Arthur's Court (1889), The Wonderful Wizard of Oz (1900), Peter Pan (1904), and The Chronicles of Narnia (1950).
The earliest modern Japanese isekai stories include Haruka Takachiho's novel Warrior from Another World (1979), Tatsunoko Production CBN collaborative Christian anime Superbook (1981), the anime film adaptation of The Wizard of Oz (1982) and Yoshiyuki Tomino's anime Aura Battler Dunbine (1983). The earliest isekai anime to involve the protagonist being trapped in the virtual world of a video game was the film Super Mario Bros.: The Great Mission to Rescue Princess Peach! (1986), based on the hit video game Super Mario Bros. (1985); the anime film adaptation involves Mario playing a video game that comes to life, making it an ancestor of the "trapped in a video game" subgenre of isekai.
Other early anime and manga titles that could be classified as isekai include Mashin Hero Wataru (1988 debut), NG Knight Ramune & 40 (1990 debut), Fushigi Yûgi (1992 debut), El-Hazard (1995 debut), and The Vision of Escaflowne (1996 debut), in which the protagonists stayed similar to their original appearance upon entering a different world. Other 1990s titles identified as isekai include the novel and anime series The Twelve Kingdoms (1992 debut), the manga/anime/game franchise Magic Knight Rayearth (1993 debut), the visual novel adventure game YU-NO: A Girl Who Chants Love at the Bound of this World (1996), the manga and anime series Inuyasha (1996 debut), and the anime series Now and Then, Here and There and Digimon Adventure (both 1999 debut). Spirited Away (2001) was one of the first isekai anime films known worldwide, although the term "isekai" was not commonly used at the time.
The role-playing adventure game Moon: Remix RPG Adventure (1997), and the Digimon Adventure (1999 debut) and .hack (2002 debut) franchises, were some of the first works to present the concept of isekai as a virtual world, with Sword Art Online (2002 web novel debut) following in their footsteps, though this categorization has been disputed, including by the series' creator.
A popular isekai light novel and anime series in the 2000s was The Familiar of Zero (2004 debut), where the male lead Saito is from modern Japan and is summoned to a fantasy world by the female lead Louise. The Familiar of Zero popularized the isekai genre in web novel and light novel media, along with the website Shōsetsuka ni Narō ("Let's Become Novelists"), known as Narō for short. The Familiar of Zero fan fiction became popular on Narō during the late 2000s, eventually spawning a genre of isekai novels on the site (especially after fanfiction was banned on Narō in 2012) which became known as Narō novels. The Familiar of Zero fan fiction writers eventually began writing original isekai novels, such as Tappei Nagatsuki who went on to create Re:Zero (2012 debut). The 2012 anime adaptation of Sword Art Online popularized the isekai genre in anime, which led to more isekai web novels being published on Narō and a number of Narō novels being adapted into anime. It was around this time that the term "isekai" was coined.
In May 2021, Kadokawa announced they would open an "Isekai Museum" in July of the same year.
In March 2024, the word isekai was added to the Oxford English Dictionary.
In many examples, the main character is an ordinary person who thrives in their new environment thanks to modern things in the real world being seen as "extraordinary" in the other world. This can be physical characteristics, such as hair or eye color, or normal everyday skills they learned in their previous life such as cooking, engineering, basic education, or medicine, which are far more advanced in the modern, real world than in the world they are sent to. In Sorcerous Stabber Orphen, an entire population of humans appear in the magically created world, transported from Earth, and are partially mixed with local dragonlike Heavenly Beings.
In many works, isekai overlaps with the harem and LitRPG genres, where the protagonist gains the affection of several potential love interests, who may or may not be human. One example of this is Harem in the Labyrinth of Another World.
The genre can be divided into two types: "transition into another world" (異世界転移, isekai ten'i) and "reincarnation into another world" (異世界転生, isekai tensei). In "transition into another world" stories, the protagonist gets transported to another world (e.g. by traveling into it, or being magically summoned into it). In "reincarnation into another world" stories, the protagonist is sent into another world after dying in the real world. A common method of death is being run over by a truck and dying, spawning the meme of "Truck-kun", a truck which appears in many isekai series that kills the protagonist and the protagonist reincarnates into a different world.
While the protagonist of a classic isekai work is usually a "chosen hero", there have been a number of alternative takes on the concept. One trend is the protagonist reincarnating into the body of an unimportant side character, or even a villain.
The protagonist is reincarnated as a villainess in a world based on an otome game, where they are given special skills. They will either try to avoid a bad outcome that will happen to them in the future or help other important characters rather than trying to antagonize them, though other characters will take over their roles as villains instead, such as in My Next Life as a Villainess: All Routes Lead to Doom!, The Most Heretical Last Boss Queen, and Villainess Level 99. Although the protagonist is usually a girl, a few works like From Bureaucrat to Villainess have a guy being reborn as the villainess instead.
The protagonist is not killed, but is instead brought to another world by magic or by an unearthly being (either a god or an alien) to help defeat a rising conflict, such as in How a Realist Hero Rebuilt the Kingdom, Chillin' in Another World with Level 2 Super Cheat Powers, and Kuma Kuma Kuma Bear. Some are given special cheat powers to help them. In I Got a Cheat Skill in Another World and Became Unrivaled in the Real World, Too, Battle Girls: Time Paradox, and Saving 80,000 Gold in Another World for My Retirement, although the chosen hero is brought to a new world, they can still travel back to their own world either at a will (either by a gateway or magical powers) or when they have completed their mission. Some works have more than one transition, such as in The Fruit of Evolution.
The protagonist is an adult reincarnated in a new world as a child with special powers after being killed, such as in Chronicles of an Aristocrat Reborn in Another World, I Shall Survive Using Potions!, As a Reincarnated Aristocrat, I'll Use My Appraisal Skill to Rise in the World, The World's Finest Assassin Gets Reincarnated in Another World as an Aristocrat, and Fluffy Paradise. In some works, such as in I'm a Noble on the Brink of Ruin, So I Might as Well Try Mastering Magic, the protagonist is reborn as a child under mysterious circumstances; whether they died in the real world or were transported to another world and turned into a child is never revealed. Some protagonists are given their powers from gods or otherworldly beings such as an alien, a magical creature, or an entity.
The protagonist is reborn in a new world, but their appearances and personalities are not altered in any way; however, they are still given special powers as well as a magical object that aids them on their journey. Examples of this are In Another World with My Smartphone, Farming Life in Another World, and Zenshu. Only rarely in anime does the protagonist return to their previous world at the end.
There are instances of protagonists that become inhuman creatures with special abilities, such as in That Time I Got Reincarnated as a Slime, where the protagonist reincarnates as a slime monster; I've Been Killing Slimes for 300 Years and Maxed Out My Level, where the protagonist reincarnates as an immortal witch; and So I'm a Spider, So What?, where the protagonist reincarnates as a spider monster. Some works have the protagonist being reborn as a sentient object, such as a sword or a vending machine, and are accompanied by another character, usually a girl.
'Villainess isekai' is an emerging subgenre within the isekai landscape featuring dynamics between transmigrated villainess that take place in otome game settings, which leaves these characters with no other choice but to take on the role enforced on them. These stories follow the main character's journey of avoiding the grim, predestined "Bad End" fate of an otome villainess. Regular isekai anime gives protagonists free will and the opportunity to achieve heroic greatness in their new lives. Isekai villainess anime feature the contrary, pinning characters in a doom-ridden role and denying them any sort of free will within the game. With most characters working against the "Villainess", the protagonist granted more agency and moral grayness than a normal "Heroine", being is thrown in a race against time to avoid the game's predestined fate.
Yandere-kei Otome Game no Sekai ni Tensei shiteshimatta you desu (ヤンデレ系乙女ゲーの世界に転生してしまったようです, lit. 'It Seems Like I Got Reincarnated Into the World of a Yandere Otome Game') and Kenkyo, Kenjitsu o Motto ni Ikite Orimasu! (謙虚、堅実をモットーに生きております！, lit. 'I Will Live with Humility and Dependability as My Motto!') are noted for popularizing the subgenre in the web novel community in 2013. My Next Life as a Villainess: All Routes Lead to Doom! aired in 2020 during COVID-19 pandemic is credited for initiating the popularity of "Villainess" anime, being quickly followed by dozens of series with similar themes and tropes in the following years afterwards.
'Reverse isekai' is subgenre of isekai that follow beings from a fantasy universe who have been transported to or reincarnated into modern-day Earth, including the anime Re:Creators. Additionally, there is also 'double reverse isekai' or 'back-to-back isekai,' where a character who has died in a fantasy world is reincarnated in the modern world (bringing modern knowledge), only to die again and be reincarnated back into the aforementioned fantasy world, often in the past, to introduce that knowledge into their original world, as seen in Doctor Elise.
'Peaceful isekai' genre includes the "slow life" approach, where the protagonist was overworked in their previous life, so decides to take it easy in the next. Another offshoot is where the protagonist uses the new world to explore an interest, hobby, or goal they had in the previous world but were unable to achieve, such as studying or opening a business, like in Restaurant to Another World.
The isekai genre became so popular during the early- and mid-2010s that it started to generate backlash, both in Japan and overseas, from those who felt that it was overcrowding the greater manga and anime market. In 2016, a Japanese short story contest organized by Bungaku Free Market and Shōsetsuka ni Narō placed a blanket ban on any entries involving isekai. The publisher Kadokawa banned isekai stories as well in their own anime/manga-style novel contest in 2017.