25 Master/Slave Relationships
in "Isekai" Manga

“Isekai” (alternate world) is the shorthand name for a genre of fantasy stories centered on an ordinary Japanese person who finds themself in a medieval-styled fantasy world where they are gifted some super power.

Basically, Isekai manga are wish-fulfilment-power-fantasy adventure stories. As such, they explore a wide variety of themes. Sometimes genres are blended together, like cooking (Restaurant to Another World), video games (Sword Art Online and Overlord), military horror (Saga of Tanya the Evil), Romance (“Black Healer”), and comedy (Hoodlum's Loved by the Spirits).

Tropes in the isekai genre can sometimes be so repetitive that stories will make fun of them. Some of these common tropes include defeating a demon lord, video game physics, exploring dungeons, talking monsters as pets (who can change into human shape), encounters with divine beings who hand out overpowered skills, harems, magic, elves and animal people, and reincarnation by truck/train/car and stabbing.

But there's one trope in particular that I want to talk about here. It's master/slave relationships. In more than a few isekai stories, buying a slave is one of the first steps a male protagonist takes on his heroic journey as an "adventurer." However, it is almost always a female slave. It is almost always a non-human slave. And there’s almost always sexual tension (and sometimes sex itself). On top of that, a few heroes will buy a sick or wounded slave, whom they heal and make into devoutly loyal and grateful servants who feel so lucky to be owned by the hero.

There’s so much to unpack in these stories. Why is slavery so popular? Why are so many slaves non-human? Is slavery a metaphor for a pet fetish or something more disturbing? Is it a commentary on the dehumanizing effects of slave trafficking? Why do so few slaves ask for freedom? What does the genre say about the nature of relationships? Why do the medieval style fantasy worlds feature slavery, but not so much the Greco-Roman or Japanese (etc.) worlds? Why do the main characters buy slaves instead of making friends?

I don’t think I’m qualified to talk about the real world implications for readers, but I think these questions are worth considering as you view the examples.

Below, I have chosen stories published by mainstream companies. The first four here have even been turned into anime and shown on English language streaming services like Funimation, Hulu and Amazon Prime.

Here is my list of 25 slavery isekai stories.

Warning: There are spoilers for slavery details.

Isekai you can watch as anime:

1. How Not to Summon a Demon Lord
(Japanese title: Isekai Demon King and the Summoner Girls Slave Magic)
STORY:

A hard core online gamer styling himself as “Demon Lord Diablo” gets summoned to an alternate world by an elf and a cat girl who accidentally get enslaved by Diablo while trying to enslave him.

2. The Rising of the Shield Hero
STORY:

Four men are summoned to an alternate world to be heroes. Three get a weapon (sword bow spear), but the fourth gets a shield and becomes the hated “Shield Hero.” So he strikes out on his own (and quickly picks up his first tanuki slave girl to fight for him).

English translation by LHTRSANSLATION

3. Death March to the Parallel World Rhapsody
STORY:

A game programmer is transported to a fantasy world. He uses his overpowered skills to save people, rescue slaves (a mix of human and non-human), and becomes the center of attention of an ever increasing group of women and girls.

4. From Common Job to Strongest in the World
STORY:

A class is summoned to another world where they become heroes with powerful hero skills. One student gets a basic matter manipulation skill. This student is betrayed and falls deep into a dungeon. There, he gains incredible skills, rescues a vampire, partners up with her, and together they search for a way back home to his world.
This isn't so much a master-slave relationship manga like the rest here, but there is slavery in this world, and the characters are prone towards the same tropey behaviors, too.

English translation by biamamscans

Isekai manga series:

5. Slave of the Magic Capital’s Elite Troops
STORY:

Magic portals leading to a demon world appear randomly across Japan, but only women develop the magic power to stop the demons. One man accidentally crosses a portal and is rescued by a member of an elite troops unit who enslaves him to draw out his life force to save their lives.

English translator unknown

6. Argate Online
STORY:

Takashi Izu is transferred to a world resembling the online game “Argate Online.” He becomes an adventurer. Soon, he rescues an elf slave who follows him, moves in with him and becomes his partner. And he visits a slave market.

English translation by LHTRSANSLATION

7. Black Summoner
STORY:

A man is transferred to a game-like fantasy world after trading his memories for skill points. He joins the adventurer’s guild and soon stumbles across a half-elf being sold in a cage. He spends two seconds pondering the evils of the world, then gets on with his new life. Eventually he decides he needs to buy that half-elf female slave to strengthen his adventuring party.

8. Changing the Structure of Skills in Another World Gained Me an Increasing Number of Rule Breaking
Cheat Brides
STORY:

A school bus of students is summoned into another world. While most choose to become heroes and train to defeat the demon lord, one student refuses and leaves to make his own way in the other world. He is immediately contacted by demons, and he agrees to buy and protect a demon girl slave in exchange for knowledge.

9. Ecstas Online
STORY:

A group of students using an educational virtual reality simulator are transferred to a game-like world. One of the students becomes the demon lord, and a fellow student (and his boss at work) becomes a slave in the demon lord’s castle.

10. I Work as a Healer In a Labyrinth City in Another World
STORY:

A university student is stabbed and is reincarnated in another world. After being fired from his healer’s job, he buys an elf slave to help him earn money in the labyrinth.

English translation by IEATLOLISCANS

11. The Princess Knight is My Classmate
STORY:

A class dies on a field trip, and one student is reborn in another world with the rare magic ability of slavemancy.

I don’t know how this isn’t an adult comic, but the manga magazine that publishes it has lots of erotic content, so maybe it is.

English translation by LHTRSANSLATION

12. Other World Elf Slave
STORY:

An elf slave and a lycanthrope slave fight over the hero who owns them.

English translator unknown

13. The Strongest Job Isn’t Hero or Sage. It’s Appraiser (Provisional)!
STORY:

A student is suddenly transported to a fantasy world and discovers he has the magic classification of “inspector.” He joins the adventurer’s guild who tells him to buy “some slaves” to help him earn money. So he does. This is one of the rare stories where a slave is male (but still non-human).

English translation by LHTRSANSLATION

14. I’m a NEET, and I Got Transported to Another World When I Went to HELLO WORK
STORY:

A man is offered an evaluation job by an employment agency. The job is to evaluate a fantasy world before it’s destroyed. He becomes an adventurer, visits a slave store where there are human slaves, but picks the cat girl.

English translation by sammy

15. The Other World Doesn’t Stand a Chance Against the Power of Instant Death
STORY:

A bus full of students are abducted to an evil fantasy world and forced to become “sage apprentices.” Lots of violence and casual slavery.

16. The Guy Who was Dragged Along to Another World is the Cheat You’d Expect
STORY:

A blatantly over-the-top fan service manga where five friends are summoned to another world to defeat the demon lord. Four are heroes, but the fifth is an accidental “normal” person. The fifth gains super powered skills (cheat skills) and is transported to another place where he rescues a slave trader, buys a cat demi-human woman, and he decides to be an adventurer.

English translation by LHTRSANSLATION

17. Making a Harem in an Other World Dungeon
STORY:

This is all about a guy who wants to gather a slave harem after being transported to a fantasy world.

English translation by Champion Scans

18. Control Skill Taker: Building a Harem from Scratch
STORY:

Summoned to another world, a man gains the “skill taker” power and gathers a slave harem. Lots of fantasized sex. And he becomes and adventurer, too.

English translation by Champion Scans

19. The Strongest Rear Guard in Another World
~ New Explorers in Dungeon Country ~
STORY:

A salaryman and his boss are killed in a buss accident and are transported to another world. They team up to fight in the dungeons, but only after he rents a “sub-human monster” slave woman.

English translation by Champion Scans

20. Even with a Growth Cheat, I Can’t Seem
to Stop Being Jobless
STORY:

A man is hit by a truck while on his way to his 101st job interview. He is reborn in a fantasy world with the ability to earn experience at 400x the normal rate, but without a job class. He quickly meets a slave trader (But it’s all for the slave’s well-being. He’s not a bad guy, honest) and buys a wolf demi-human woman to be his partner for adventuring (and to save her from a noble who wants to buy her).

21. I Won 4 Billion Yen but I Moved to Another World
STORY:

Not only does Kazura win the lottery, but his parents house has a magical door to a fantasy world. Kazura travels back and forth between worlds helping out the people there. And a human(!) slave woman falls in love with him. Like they do. Like all the women there do.

22. I Reincarnated as a Sword
STORY:

A man is reincarnated as a magic sword. A young cat slave girl finds him. He kills her very bad owner. They team up and she names him “Master.”

English translator unknown

23. Torture Princess of Another World
STORY:

A son is killed by his father, and the son’s soul is scooped up by an evil woman in a fantasy world. She turns him into a golem to be her slave. Yet somehow she’s the one who keeps getting put in bondage. The son eventually gets a slave of his own, too. She’s some kind of automaton, of course.

24. God’s Eye Hero
STORY:

Maruta is a shut-in who is summoned by an evil goddess who wants to use him in her power games. However, she finds him lacking and dumps him in a fantasy world where a good goddess gives him a magic eye. His first visit to a town results in rescuing three naked slave women in a well (and they are human!). They become his followers. He joins the adventurer’s guild. He turns out over powered. His preferred weapon and special skill is as a giant log wielder (no metaphors there at all, right?)

English translation by LHTRSANSLATION

25. Magic Eye and Bullets
STORY:

A man is stabbed, dies, and is reborn in another world with a magic eye and a rifle. After saving a noble girl, he asks the girl’s father for information about the town they live in. The noble’s servant immediately suggests buying a slave. So, naturally, he buys a traumatized and disfigured rabbit girl whom he heals and puts to work fighting with him.

English translation by EHJR SCANLATION

These were 25 isekai stories that feature master/slave relationships. There are an overwhelming number of isekai stories to choose from, and there are also other types of fantasy stories which feature slavery and master-slave relationships, too, but I'll save those for another list.

by Faviola Llervu (Sep 12th 2019)

PS: When needed, I flipped the sample pages to make reading easier for anyone unfamiliar with manga reading direction. This means I had to re-flip the text, and during the process, I removed the weeby "san" and "sama" suffixes some translators added.