This manga provides examples of:
- And I Must Scream: The holes are somehow shaped so that you can only move forwardnote .
- Most likely the walls of the cave are ridged in a sawtooth pattern,◊ making it more difficult to go against the flat part of the ridge as opposed to the slanted part.
- Body Horror: There are better ways to go on a diet.
- Catapult Nightmare: Provides the trope page image.
- Claustrophobia: You will have it by the end of the story.
- Daylight Horror: Most of the creepy stuff happens at daytime.
- Dreaming of Times Gone By: Everyone who has a hole carved for them.
- Eldritch Location: There is something seriously wrong with the fault and the holes running straight through it.
- Fan Disservice: People usually undress in order to fit into the holes, and not all of these people are attractive. Owaki stripping to his underwear (or less, considering the fact that we only see him from the waist-up) would be fanservice if not for what will eventually happen to him.
- Fate Worse Than Death: In Owaki's dream, he is a man from a primitive tribe condemned to a hole for an unforgivable crime.
- Impact Silhouette: Inverted. The holes were already there and each one is seemingly tailor-made to resemble a specific person. Anyone who finds their hole is then compelled to enter it.
- Noodle People: Literally - when people enter "their" hole, they are stretched in every direction until their limbs are thin like tentacles, yet are still alive.
- Oh, Crap: The ending.
- Primal Fear: This manages to hit isolation, darkness, the unknown, claustrophobia, and body horror all in one fell swoop.
- Schmuck Bait: A prime in-universe example.
- Shown Their Work: As per the dream, there were people in Japan as early as 50,000 BC. They also developed stone-carving technology remarkably early.
- Token Romance: It was really unnecessary for Owaki and Yoshida to get together. It happened so that we'd get a giant Hope Spot, before things get worse.
- Written Sound Effect: The first guy's sounds (in the Japanese version) are ズズ and ズポツ, and the protagonist's is ズ…ズ…ズ. The first two are rendered "SSLL" and "SLIP", but the last is the famous, "DRR... DRR... DRR". Which, apart from being a nonexistent Japanese phoneme (it could be "ZU... SU... ZU"), this transliteration is so obtuse that people are apparently under the impression that this is the sound of the disfigured peoples' groans rather than the sound of them sliding through the tunnels. These are squicky sounds, people!
"It's slowly coming this way!!" DRR... DRR... DRR...