The Isekai genre is an immense, sprawling forest of trees, each with twisted and interconnected roots. Vast and towering trunks loom high above, stretching off and up into a dreaming dark, leaving us to step between them, and peer down into the pools of collected water between them.

Here and there, we can see the ways these pools formed. The things that make them the same, and the things that make them different. Ancient stories, old enough that we don’t even have the source any more; stories old enough that we have twelve versions of the same story, with different characters and meaning, but still the story of someone who wandered through a fey portal or who went to live with a fox spirit or anything like is the same basic idea.

Ah, the idea? Isekai is a shorthand term we use in the west to refer to, usually anime, stories about a character who starts in our world and is transported to another world. Most often, nothing passes from one to another but knowledge, and the result is a character you can directly relate to because of their commonality with you, as they learn about a world you know nothing about.

Isekai is something there’s a bunch of easy criticism for, which makes sense because it’s been extremely popular lately (and by lately I mean ‘at any given point in the past century’), and recent media production has made a lot of bad isekai really obvious. I’ve even seen the position that isekai is an inherently weak storytelling structure because it betrays an author who wants to ‘avoid’ world building.

If you check Wikipedia, the earliest isekai story they point to is the story of Urashima-Taro, which was a folklore store in the Meiji era. I say it that way because it’s hard to nail down whether that’s literally the exact first time the story ever showed up, or if it was a derived story from another, earlier story. The story of Urashima-Taro is about a fisherman who gets whisked away to a kingdom of the turtle princess, and it has a moral about asking for directions and stuff. Even one of the earliest anime was a retelling of this story.

Anime has enjoyed the isekai as long as I’ve been alive, and it is, like many things, subject to trends, often in clouds of media. Anime is always a reactive, short-term franchise space so you’ll have one successful idea that then gets a dozen imitators or near-imitators. The earliest isekai I remember seeing was Escaflowne, which was also an anime about a girl travelling to another world to get herself a collection of hunky waifu boys. That was also around the time of Fushigi Yugi, another anime with a similar idea. There were others, too – you can look at El Hazard in the same rough time period (though I didn’t discover it until much later). Heck, when Ranma 1/2 ended, I was excited to tune in for her take on an isekai show, in the form of Inu-Yasha.

By the way, this idea of a relatable modern protagonist travelling to another world where the rules are all different but so they can give you information about that world framed as per now? Bleach probably counts too.

Anyway, that’s like, foundational narratives about Isekai in Japan. You might also see them called looking glass stories, with narratives like Alice in Wonderland touching on some of the same idea space. There’s also the Oz books by Frank L Baum, which are the basis of the movie The Wonderful Wizard of Oz and thousands of spinoffs. Over time, they seem to discard the isekai element, but they’re typically seen as relatives of the form.

Comic books also have a lot of Isekai stories, and a number of time travel stories take on the same basic structure – you have a character who’s like here and now and how they relate to the then and there is something they can frame in terms of our familiar things. There’s also the reverse version of this narrative, like a number of ‘time traveller comes forward to now’ stories like Kate & Leopold, which is trash.

This is where people who get really nettled about genre and try to treat things like there are clear, tight boundaries get mad at me. I’m implying that Kate & Leopold is an isekai, alongside such anime of the form as Fushigi Yuugi and Inu-Yasha. This is one of those things about genre in general: It’s not clear and it’s not specific, even if you want to act like it is. If you add a lot of caveats, you’ll lose things you think are definitely isekai and if you make it wide open, you’ll include things you might not think count.

The modern isekai is influenced further by its own self-reference. Characters in isekai stories being made cheaply in Japan are at the stage where they are literally referring to ‘being isekai’d’ or ‘this is an isekai world.’ Like that’s showing up in the titles of these series.

Something I’ve noticed about recent isekai offerings like That Time I Got Reincarnated As A Slime , Ascendance of A Bookworm or Mushoku Tensei : Jobless Reincarnation, is that uh, some large number of recent, popular anime start with the idea of ‘hey, what if this life I have here, in this world, with its jobs and debts, ended, and I got to go somewhere I like instead.’

And that’s…

Kinda unsettling?

Like, the whole point to me was that isekai settings let you start with someone relatable and ‘dying would be better than my job’ is a pretty dire thing to be able to use as a common cultural reference point.

(There’s also a bunch of isekai about videogames, like virtual worlds people get stuck in, but they’re very boring to me.)