“What Happens Inside the Dungeon” is an 18+ Korean webtoon (manhwa) by Reva that mixes fantasy dungeon crawling with explicit erotic comedy and worldbuilding.

Quick Scoop

  • The story follows an innocent young adventurer named Cheong who travels to a far‑off land to hunt monsters and gain fame, only to discover that this world treats monsters and dungeon loot as intensely sexualized resources.
  • The inciting incident is the death of the legendary Swordmaster Hoss while fighting the powerful Shell Dragon; what people find with his body triggers a new “sexual hype” around monster spoils.
  • The series is explicitly adult: it combines sex, fetish‑leaning monster ecology, and comedy, with some genuine character development and emotional beats.

Setting and Premise

The series takes place in a fantasy world where dungeons and monsters are part of daily life, but the twist is that almost every aspect of the ecosystem can be repurposed for erotic or pornographic use.

  • Monster parts are harvested and sold as sex aids, drugs, or adult commodities instead of just weapons or potions.
  • Inns, adventurer culture, and even items like ore and snakeskin are folded into sexual humor and uses.
  • This “perverted” economy becomes a social phenomenon, shaping everything from blacksmith work to adventurers’ motivations.

An example often cited is that in the “starter inn,” even basic hospitality includes adult products, signalling to the reader that this world normalizes sexualization in absurd, comedic ways.

Main Characters and Dynamics

Cheong (protagonist)

  • Cheong is portrayed as an earnest, somewhat naïve adventurer who initially just wants standard RPG rewards: glory, gold, and monster hunting.
  • Everyone around her assumes she’s really here for the sexual side of adventuring, which drives much of the comedy and misunderstandings.
  • Her reactions—confusion, embarrassment, gradual adaptation—anchor the reader as she navigates an increasingly bizarre dungeon culture.

Supporting cast

A key supporting character (highlighted in fan spotlights) is a woman who is:

  • Medically “frigid” in‑world, using extreme levels of sex, drugs, and masturbation as a form of “therapy,” which is played both for dark humor and character quirk.
  • A sushi chef whose skills translate into being an elite assassin who can turn giant monsters into sashimi platters, blending culinary craft, violence, and erotic framing.

More characters join later, each bringing their own sexual eccentricities, fighting styles, and emotional baggage, helping balance lewd jokes with a sense of a living party of adventurers.

What Actually Happens in the Dungeon

Inside the dungeon, the series blends lewd traps, dangerous monsters, and surprisingly coherent worldbuilding.

Erotic ecology and traps

Examples from commentary and summaries include:

  • A carnivorous, house‑shaped pitcher‑plant monster that dissolves victims’ clothing and emits aphrodisiac gas before trying to drown and consume them, mixing genuine danger with fetish imagery.
  • Monster‑derived items whose shapes or properties make them ideal as sex toys or improvised protection, such as mushrooms shaped for insertion or snakeskin repurposed as extremely effective condoms.
  • A special ore that only virgins can hold safely; because most miners and blacksmiths cannot touch it, it’s treated almost like worthless scrap despite its potential.

These elements are not just throwaway gags: they tend to recur when the plot demands creative solutions, making the dungeon feel internally consistent despite the absurd premise.

Fights, quests, and stakes

  • Cheong and her allies still fight monsters, clear areas, and take on quests, so the series retains the structure of a combat‑driven fantasy story.
  • The “big picture” conflict involves demons and power struggles in this hyper‑sexualized world, with the dungeon acting as both battlefield and marketplace of bizarre resources.
  • Action scenes and emotional beats are often punctuated by over‑the‑top sexual comedy, creating intentional tonal whiplash: a serious fight may immediately be followed by a sex‑comedy payoff.

Themes, Tone, and Reader Reactions

Tone

The tone is a mix of:

  • Sex comedy: exaggerated misunderstandings, ridiculous monster‑based sex tech, and characters treating wild situations as everyday problems.
  • Action fantasy: real stakes in fights, injuries, and world‑level threats.
  • Occasional drama: characters’ traumas, insecurities, and relationships are explored enough to make readers care beyond the NSFW content.

Commentary videos describe it as “sex, action, comedy, and a little bit of JoJo‑style randomness,” emphasizing how eccentric and flamboyant it can get.

Themes

  • Body and desire : The story uses monsters and loot to explore desire, inhibition, shame, and pleasure in a heightened, comedic way.
  • Economy of perversion : The dungeon’s resources literally fuel a sex‑based economy, poking fun at how fantasy worlds monetize anything.
  • Found family and growth : Despite the raunchiness, the party dynamic and character arcs lead up to a reportedly satisfying ending and epilogue that tie off emotional threads, which many fans praise.

Forum and “Latest News” Angle

Recent online discussions frame it as:

  • A cult‑favorite 18+ manhwa recommended for readers who are comfortable with explicit sexual content and want both laughs and surprisingly solid storytelling.
  • A standout among “sex world” stories because it integrates sexual elements into the dungeon’s ecology and plot rather than just using them as shallow fanservice.
  • A completed series with an ending and a short epilogue (often highlighted in video breakdowns) that avoids the rushed finales common in similar works.

Because of its explicit nature, you’ll mostly see it discussed in adult‑oriented communities, manhwa forums, and NSFW recommendation threads rather than mainstream platforms.

Is It for You?

You might like “What Happens Inside the Dungeon” if you:

  • Want a dungeon‑crawl story that leans hard into sexual humor and adult themes.
  • Appreciate detailed, somewhat “logical” worldbuilding even in a lewd premise.
  • Prefer finished series with a planned‑feeling ending and epilogue.

You should probably skip it if you’re uncomfortable with explicit sexual content, fetish‑oriented comedy, or tonal whiplash between danger and erotic humor.

Information gathered from public forums or data available on the internet and portrayed here.