Inside the Cave of Obscenity (18+)

Alternative Name: 淫靡な洞窟のその奥で
Author: Ume Tane / ウメ種
Artist: Afu Kuro / アフ黒
Category: Japanese Light Novel, Fantasy, Smut
Status: 5 Volumes
Source: –
Translator(s)/Translation Group: Ziru’s Musings
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A world where the [Demon King] was defeated by a [Hero] that came from another world. People carelessly forgot about their fear of the [Demon King] and of monsters, living peacefully.

In a forgotten and run-down cave in the mountains, a new monster that should not have been born was given birth.

The monster’s name was the [Black Ooze]. It was nothing exceptional other than its black color, an ordinary slime.

However, this slime had the special characteristic of being able to take the abilities of the living things it swallowed. It preyed on an insect that had paralytic poison, as well as other animals. Following that, it attacked a human, obtaining his knowledge and [Desire].

Before long, the monster established its target as the female mage that came to explore the cave.

This world still wasn’t aware.

[A Monster Was Born]…

Warning: Depictions of Rape

If you enjoy this translation, consider buying an original copy of the series in its native tongue to support the author.

eBook Store Page: Volume 1Volume 2Volume 3Volume 4Volume 5


Volume One
Chapter 1 – The Day It Was Born
Chapter 2 – Adventurers







Volume Two

Chapter 1 – Fresh Prey
Pt1 Pt2 Pt3

Chapter 2 – The Abandoned Mine’s Investigation
Pt1 Pt2 Pt3 Pt4 Pt5 Pt6

Chapter 3 – The Adventurers Who Fell
Pt1 Pt2 Pt3

Chapter 4 – The Knight Order’s Dispatch
Pt1 Pt2 Pt3 Pt4

Chapter 5 – The Female Knights’ Dignity
Pt1 Pt2 Pt3 Pt4

Chapter 6 – A Pleasuring Corruption
Pt1 Pt2 Pt3 Pt4 Pt5 Pt6

Chapter 7 – The Female Knights’ Fate
Pt1 Pt2 Pt3 Pt4 Pt5





Volume Three

Prologue – Escape
Chapter 1 – Crucible of Pleasure
Chapter 2 – In the Royal Castle
Chapter 3 – Creeping Unnoticed






Volume Four








Volume Five


54 Responses to Inside the Cave of Obscenity (18+)

  1. LeTouriste says:

    Pretty good,i can’t wait for more:)

  2. ravencraven says:


  3. ravencraven says:

    r u guys going to any updates on this series or the updates just going to be done ziru’s musings?

  4. darkmist says:

    Love this 😁
    Please update as much as you can 🙏

  5. . says:

    There should be a donation page for this to prompt the translator to translate faster!

  6. Crywolf641 says:

    Hahahaha i like this already! Just reading the description get me on!

  7. SanKyu says:

    Seconded on that donation page. This one is quite different from the other 18+ novels I’ve read, given its unique protag. Really hoping for more releases soon!

  8. taetaetik says:

    thank for the chapter, it’s interesting in a slime that be truely a slime 55, can’t wait till vol 5.

  9. habib says:

    So much of tenticals. 🤒

    I thought sooner or later the slime will assume the form of a man, and infiltrate the town. 😎

    But that, sadly, did not happen. 😑

  10. Weabookun says:

    Many thanks for translating this. Damn, vol 5 cover is interesting, as it shows that the queen is fighting back.

  11. FapTactics says:

    Continual orgasms are my fetish.
    I did NOT expect to find my #1 fetish while looking for an interesting LN to read…
    I really hope this project doesn’t get completely dropped because I’d highly enjoy reading all of these.

  12. traxer says:

    Will he get some sanity in future?

  13. target_prac114 says:

    Are these 5 volumes the complete series or is this an ongoing project?

  14. Kx4 says:

    I hope this would be an anime..

  15. Guest says:

    Is there a Chinese name for this?

  16. BlackElite says:

    I was lured to the dark side….thank you for your enlightenment and guidance….

    (I hope you’re having a good time)

  17. jaidrago says:


  18. lemon says:

    hello m8, the damm “”By continuing to use the site, you agree to the use of cookies. more information [Accept]””
    dosent want to go away even when i press the button and refreash. can you do something about it? if not its cool

    • Ziru says:

      I’ll tell Joe (the person that manages that stuff) about it.

      Does it disappear on the page you use it only to reappear on the following page, or does it ignore your click on it entirely?

      Also, if you have cookies disabled or are using incognito mode, that’ll cause it.

  19. Thomas says:

    Great post! Have nice day ! 🙂 unfpz

  20. Anonymous says:

    Just a friendly reminder that you’re doing Hentai-Jesus’ work my dude.
    Keep on being amazing!

  21. ANON says:

    No updates after so long. WAS this dropped?

  22. NTR Baron says:

    While ntr is my thing, the first thing I liked was tentacles then ahegao so.. TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!TENTACLES!PRAISE THE ALL MIGHTY SLIME TENTACLES!!!! moving on, this is the first 18+ novel I would love to see have an anime(hentai) adaptation.

  23. Eugene Jovic says:

    This should definitely be made into an anime. I love this series so much and would love to see what someone, such as ghibli studios could do with this novel; it is just so amazing!!!! [Fukyun!]

    • NTR Baron says:

      Ghibli? Dude that’s a studio that focuses more on younger viewers, this is better if it gets an anime adaptation by studios like Collaboration Works or PoRo or Office Takeout or Seven for quality ero anime works and if this also gets a game adaptation then Black Lilith or Tinkerbell(Chaccu) or Pinpoint could make this a gem.

    • Celeb says:

      What happened to weekly/bi-monthly updates?

  24. Anonymous says:

    T.T update died

  25. Anonymous says:

    I přes for an update 🙁

  26. Anonymous says:

    not like this dont die

  27. Anonymous says:

    Don’t die, Ziru…

  28. Sonsuka says:


  29. Anonymous says:

    RIP? 🙁

  30. Anonymous says:

    Is this series still being translated?

  31. Anonymous says:

    What happened to the parts of volume three, chapter 1 that was already posted ? It’s gone now.

  32. Nick says:

    What happened to the parts of volume three, chapter 1 that was already posted ?

  33. Luna Ray Akuraito says:

    Hello? Did Ziru break a promise and actually drop this?

    • Shiro says:

      It’s good I don’t read more than 3 chapters? And I have another guestion that slime will always do everything on instinct or will get self awareness?

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