The story involves the existence of a race of flesh eating creatures called Shokujinki (食人鬼, Man-Eating Ogres), they remain hidden among human-kind while feasting on them secretly. A martial-arts styled school known as Kifuuken (鬼封剣, Ogre-Sealing Sword) was founded to combat the menace, training and arming combatants to face the Shokujinki threat, with the teachings formerly passed down through the Momota family. The story follows the forbidden romance between Toshihiko, the latest heir of the Kifuuken school and Yuka, a young woman who is one of the monsters.
This work includes examples of:
- Ax-Crazy: Flesh Eaters are all like this. Some can resist the urges, but once they transform they lose control of their senses.
- Art Shift: Some pre-opening scenes feature completely different art and animation style.
- Bizarrchitecture: O.Q. headquarters. It sort of resembles a normal skyscraper at the base, but as you get higher the architecture gets so monstrous and twisted it verges on Alien Geometries.
- Body Horror: The monster transformations. Ooba's lab. Ooba himself.
- Breaking Speech: Ooba uses these constantly, mostly just to watch people squirm. He dies due to one, where Toshihiko attempts to kill them both just to shut him up.
- Can't Have Sex, Ever: Toshihiko and Yuka try to have sex but can't (which frustrates them to no end) because Yuka keeps transforming when she's turned on.
- Censor Box: ...and censor scribble, covering Toshihiko's and Kazuma's naughty bits.
- Chekhov's Skill: The paralysis technique, which Yuka uses in the last episode, but it fails to stop Toshihiko from following her.
- Cool and Unusual Punishment: With creative use of sedatives, warm water, and a chainsaw, Gakutou and company make Toshihiko believe he's being dismembered one limb at a time, without giving him so much as a papercut.
- Cruel and Unusual Death: Turning into an Eldritch Abomination then eaten alive by the nice young woman you had helped out qualifies.
- Dangerous Forbidden Technique: The Kemonozume, which involves cutting off your own arms and putting a monster's arms in their place. It drives the user mad.
- Determinator: Toshihiko takes unbelievable amounts of punishment and hardly breaks stride.
- Eldritch Abomination: The monsters; the natural born ones don't have eyes.
- Fallen Hero: Kakitoki Jin was so obsessed with surpassing Toshihiko's father that he used the Kemononozume and was overwhelmed by it, killing many innocents. Ooba went insane after witnessing this personally.
- Full-Frontal Assault: In the last couple of episodes, both Kazuma and Toshihiko fight Ooba completely naked.
- Gentle Giant: Bon Ooba is a wandering detective who's at least two stories tall, and a total sweetheart to everyone he meets.
- Gorn: Lots of blood and violence here, because it aids the deranged animation.
- Gory Discretion Shot: Sometimes it happens, sometimes it doesn't.
- Hard-Drinking Party Girl: Yuka develops an alcoholic streak while she and Toshihiko are on the run. This is played for drama because alcohol makes it easier for her to change.
- Idiosyncratic Episode Naming: It's not apparent from the English translation but all episode titles contain references to flavors.
- Informed Ability: Rie is a swordswoman, but we never see her fight with a sword.
- Kirk Summation: Bon Ooba is the only person to render his father speechless through words alone.Ooba: Without strength, you can't do as you please! Don't you want the power to do anything you want?Bon: ...I want to be friends with everybody. Papa, you don't have any friends, do you?Ooba: ARRRRRRRRGH! *click*
- Large Ham: Ooba's every line and expression is larger than life and this is emphasized by his unique face. After he's revealed as the villain, he really goes off the deep end.
- Laughing Mad: Ooba, master of the Evil Laugh.
- Love Triangle: Kazuma loves Rie who loves Toshihiko who loves Yuka.
- Also a Sibling Triangle since Toshihiko and Kazuma are step-brothers (in fact, as it turns out, half-brothers).
- Magic Pants: Usually played straight with the Flesh Eaters when they transform but averted with Kazuma at the end, who is totally naked after his transformation.
- Mind Screw: The series gets progressively more like this and the last episode takes the cake.
- Older Than They Look: Yuka is about 30, but is often mistaken for younger.
- Pet the Dog: Ooba seems to do this with his son, but it comes off as extremely shallow and self-serving.
- Proper Lady Yuka fits this to a tee assuming you discount her occasional transformations into a ravenous monster.
- Say My Name:
- OOOOOOBAAAAAAA!
- Kakitoki Jin also gets in on the act, turning it into a Madness Mantra:
Ri...e...Ri...e...Ri...e...Rie. Rie. Rie. RieRieRieRIERIERIERIE! - Straw Nihilist: Ooba is all about this in the latter half of the series.Ooba: This is reality. Maddening, dreamless truth...People only act out of self-interest! Emotions are just chemical reactions! Memories are POINTLESS, USELESS DATA!
- Talking Is a Free Action: Subverted and weaponized. In the final episode, Ooba gets Toshihiko monologuing about why he cares for Yuka, and then cuts his arm off when his attention wanders. Then Ooba immediately starts crowing about how weak they are...and Toshihiko takes the opportunity to decapitate him.
- The Rival: Kakitoki Jin to Toshihiko's father, in their youth.
- Unlucky Childhood Friend: Rie to Toshihiko and Kazuma to Rie.
- Vapor Wear: Yuka rarely wears a bra, but her breasts are small enough that she doesn't need one. She's seen putting one on in episode 6, but the dress she's wearing would show the straps.
