Isekai Quartet

Isekai Quartet

Isekai Quartet anime series cover art
Isekai Quartet


Isekai Quartet (異世界かるてっと) is one giant cross-over episode in series form. And it doesn’t just cross over two or three anime, but four of them (hence the “quartet” in the title). But, as is the case with most cross-over episodes, it’s actually worse than the individual series which make it up.

The plot goes something like this: characters from four different isekai anime get isekai’d into another world in which they have to play school. The only way for them to be returned to their own “other worlds” is to come together as a class. Also the teachers at this school are from their various worlds.

So as you can see, there’s not really much of a meaningful plot here. But, that’s not really the point anyway. The point of this series is to see characters from your favorite isekai anime interacting with each other. It’s fan service, pure and simple.

Luckily, the four isekai in this cross-over are actually the four best isekai around. And, although the ratings I gave to each of them may not fully align with that sentiment, it’s the truth. For example, I gave How Not to Summon a Demon Lord a higher score than Overlord, but I’d still rather watch Overlord.

Different Worlds

Speaking of Overlord, that’s one of the series featured in this anime. The other three are The Saga of Tanya the Evil, KonoSuba, and Re:ZERO. And, while this might be a minor spoiler, at the end of the season we’re told that some transfer students are coming into the school. Does this mean the quartet is going to become a quintet?

I’m not so sure about that. It’s possible that another series will be added to the mix, but there are two reasons I think this won’t be the case. First, it would no longer be a quartet. Second, what other series would be added? I honestly can’t think of another one that I would want added to the mix.

Aqua, Albedo, and Rem from the anime series Isekai Quartet
Aqua, Albedo, and Rem

Anyway, this school world is a bit different than the other worlds our characters come from. The most notable difference for the characters themselves is that it’s peaceful. While Ainz and Tanya are wary of this, Kazuma and Subaru are fully accepting of their new life — Kazuma more so.

Each of the characters also retain their abilities within this world. That means Kazuma can still steal panties, Ainz and Tanya are still overpowered, and Subaru can still force himself to have a heart attack by trying to tell someone he can return by death.

However, it’s implied that Subaru’s actual return by death ability is nullified in this world. So basically while everyone else gets to keep their cool powers, Subaru only keeps the demerits of his.


Overlord is the series of the bunch which I would rate the lowest. I think it has a great story and some pretty good characters, but it has a major flaw. That flaw is that it uses bad CGI, and the usage of bad CGI increases with every passing season.

The characters from Overlord which are in the main class in Isekai Quartet are Ainz, Albedo, Cocytus, Aura, Mare, Shalltear, and Demiurge. Basically all of the floor guardians of the Great Tomb of Nazarick. These are the ones who aren’t here to mess around and make friends (other than Ainz).

The Saga of Tanya the Evil

Tanya the Evil is the only one of these series I haven’t actually reviewed yet on this site. The reason being that I’ve actually seen all of the first season except for the first two episodes. At some point I’ll go back and rewatch the series in its entirety.

The characters from Tanya the Evil which are in the main class are Tanya, Viktoriya, Erich, Matheus, Warren, and Rhiner. While Tanya takes this situation very seriously because she believes it’s the work of Being X, her men don’t seem to mind all that much.


KonoSuba is my personal favorite isekai anime. It’s also the highest rated comedy series I’ve ever watched. The KonoSuba characters in the main class are Kazuma, Aqua, Megumin, and Darkness. As a side note, while most side characters are in the second class, Yunyun is alone in the third.

Darkness, Kazuma, Megumin, and Betty from the anime series Isekai Quartet
Darkness, Kazuma, Megumin, and Betty

I also like how the KonoSuba characters react to this situation the most — aside from Darkness since she’s my least favorite. Aqua just wants to be in charge of everyone and kill the undeads, Megumin wants to show off, and Kazuma wants to stay in this world forever so he doesn’t need to go on adventures with his useless party.


Re:ZERO is my second favorite isekai anime. The characters from this series are the most accepting of the new world in which they find themselves, though they would like to return home at some point. The characters in the main class are Subaru, Emilia, Betty, Puck, Rem, and Ram.

Subaru, Emilia, and Rem in particular have fully embraced their new school lifestyle, even more than Kazuma who doesn’t want to leave. Rem and Albedo even strike up an unlikely friendship due to them being completely obsessed with their respective series protagonists.


In the end I had to give Isekai Quartet a 6/10 because while it was enjoyable, it wasn’t that enjoyable. I felt like there was a lot of inter-series interactions missing, as the majority of the characters stuck to their own groups.

Also, we never got a conversation between Megumin and Emilia. I really wanted Rie Takahashi (the voice actress of both of them) to have a conversation with herself. That just seems like a huge missed opportunity right there.

But which series featured in Isekai Quartet is your favorite? Are you team Overlord, Tanya, KonoSuba, or Re:ZERO? Also, if a fifth isekai anime was to be thrown into the mix, which one do you think it would be? Or which one would you want it to be? Let me know in the comments.

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My review of season 2 is available here.

One Reply to “Isekai Quartet”

  1. I’ve never watched the other series but I love KonoSuba. If I had to choose a new series to fit the world of Quartet I would go with How to Not Summon a Demon Lord despite thinking the chances of this happening is negative. If Kazuma is already pissed of by Subaru’s “perks” of having good and powerful allies plus pretty girls without quirk traits, just imagine his reaction when meeting Diablo and learning that he does not only have a huge harem of gorgeous and cute girls whom would risk their lives for him but he himself is extremely overpowered and can defeat anything in a blink? God, I can just imagine Kazuma trying to kill himself just to go back to his peaceful place with his true heroine Eris.

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