Ogre Slayer (鬼切丸 Onikirimaru) is a manga series created by Kei Kusunoki. The manga has been adapted into a 4 episode OAV which was the first production of OLM Incorporated. A prequel, Legend of Ogre Slayer (Onikirimaru-Den''), set in medieval Japan, is currently being released, by the same creator.
Ogre Slayer is about a young man who hunts ogres. The young man was born of an ogre's corpse, like the oni born of human's body, making him pure ogre blood. Though he was born like an ogre, he has the appearance of a human. Instead of being born with horns like traditional Japanese ogres, he was born with a sword. The young man doesn't have a name, but his sword is called Onikirimaru, the Ogre Slayer.
Note: In original language Ogre is "Oni", demons of Japan tradition
This series contains examples of:
- Absurdly Sharp Blade: Onikirimaru, who usually has no problems slicing through ogres.
- Asshole Victim: The series has a lot of horror elements and often the first victims of a story are people who are abusive to their servants, bandits, or in modern Japan, Japanese Delinquents and gangsters.
- Becoming the Mask: He calls himself a demon, and is happy to continue spreading the rumor that he was born out of one, even though his retcon origin is that he was sent by the gods themselves. Of course, he also absorbed the demon's essence during his birth so he's kinda a demon in that way.
- Bitter Sweet Ending: Onikirimaru can’t save everyone and some of the characters are their own worst enemies or they get in over their heads. Generally at the end of each story, only 1 or 2 of the characters is still alive by the time the Oni has been slain.
- Been There, Shaped History: Onikirimaru, in the prequel/sequel.
- Born Lucky: One of the Ogre hosts has escaped many accidents unhurt, turns out it's because the ogre is just protecting it's host.
- Cool Sword: Onikirimaru, one of the few things that can surely kill an ogre.
- Creepy Child: Many stories have teenagers possessed by an Oni or were raped and are carrying an Oni child. There are other stories of Oni being born from incestuous relationships. The Oni in the chapter "Tag" is revealed to be an Oni that looks like a child but is implied to be over 50 years old. The Oni eats anyone who 'loses' tag to him. It is implied he may have killed his whole family off due to his mother's incestuous relationship with her brother.
- Darker and Edgier: The OVA compared to the manga.
- Empathic Weapon: Onikirimaru won't hurt the nameless hero as it's actually part of him.
- Equivalent Exchange: Some of the ogres will grant a human a wish, it's not until later when they realize the price they have to pay for it.
- Foil: In Onikirimaru-den, Suzuka Gozen and Onikirimaru are this. Onikirimaru was born out of a nun, devoured by Shutten Douji and hates humanity because he feels they didn't help his human mother, but will still slay demons because they killed his mother. Suzuka Gozen was a demon who fell in love with a human, gave birth to a human child and loves humanity. In their encounter, Suzuka tells Onikirimaru that she shall observe him until he loves humanity and desire to become human, which by present day, he does.
- Gorn: Borders on
Narm at times. - Humans Are Bastards: Ogres are not the only ones doing evil deeds in the world; in fact, some of the evil deeds humans do end up giving up birth to Ogres.
- Hunter of His Own Kind: Onikirimaru, born out of an Ogre, hunts Ogres. This is actually revealed to not be entirely the case in the sequel series.
- I Just Want to Be Normal: Onikirimaru, whose quest to kill all of his kind is done in the belief that once he completes this nigh impossible task, he will become human, get a name of his own and live a normal life.
- Knight Errant: Onikirimaru is basically this, wandering the land and slaying any Oni he encounters or his sword alerts him to. Interestingly enough, most Oni know who he is once he attacks or appears before them, often mocking his desire to be human. Despite most Oni not keeping in contact with one another, they seem to have a strong word of mouth with regards to Onikirimaru's mission.
- Kick the Dog: Ryoko, the maid, get's constantly abused by the rich family she serves.
- The Nameless: The main character has no name, but is referred to by the name of his sword as a placeholder.
- The Messiah: Onikirimaru-Den reveals that he's a child of the gods, sent to earth thru a Mystical Pregnancy, in order to protect humanity from the demons.
- Dark Messiah: However, because men tasked with protecting her mother failed, he harbors resentment towards humanity.
- Metaphorically True: Onikirimaru was actually born from a nun that had been devoured by the demon Shutten Douji, but in the process of being born, he absorbed Shutten Douji's essence and burst out from the demon itself, giving the impression he was born from a demon.
- Noble Demon:
- Onikirimaru, by default, specially given he's the protagonist
- Benkei, a demon loyal to Minamoto no Yoshitsune, who fought against an army in order to give his master time to commit seppuku undisturbed.
- Suzuka Gozen, a demon princess that became sorta-human after falling in love with one and giving birth to his child. She also fights demons because she loves humanity.
- "Not So Different" Remark: Onikirimaru does remark this about himself and Ryoko; he also remarks this about some humans and ogres.
- Older Than They Look: Onikirimaru, being several hundred years old.
- The main villain in one chapter is a child who is really at least 50 years old. His own mother had him due to an incestuous relationship with her brother.
- Oni: The main antagonists of the story.
- Our Demons Are Different: The Oni seen in the manga cover their wide history of different mythologies and urban legends. Some oni are spirits that possess humans to get a body. They can have a wide variety of mystical powers, be spirits, and be alive at the same time. Humans will turn into Oni if they are possessed, feel intense hatred for others, or make a deal with an Oni.
- Only Known by Their Nickname: The nameless hero is most commonly known as Onikirimaru, which is the name of his sword.
- Pet the Dog: Onikirimaru to Ryoko, the maid.
- Really 700 Years Old: Onikirimaru, again, being actually born during feudal japan.
- Retcon: Onikirimaru-den, the prequel, changes Onikirimaru's origin to be a child of the gods. The demon Shuten Douji devoured his mother, while he was still in her womb; during the process, he absorbs Shuten Douji's essence and bursts out from his insides, sword in hand, killing him.
- Sealed Evil in a Can: Some ogres start the stories this way; Onikirimaru unseals them himself so they can be properly slain.
- Stepford Smiler: Ryoko, and Onikirimaru, both tend to smile
- Takes One to Kill One: He is a pure-blood ogre, despite his looks. Later retconned.
- Tall, Dark, and Handsome: Onikirimaru, given his origin and his goal.
- Tall, Dark, and Snarky: He's also a bit of an ass, but it's kind of warranted.
- Too Dumb to Live: Some of the ogre victims.
- Too Good for This Sinful Earth: Ryoko in the original series. Onikirimaru's mother in the prequel/sequel.
- Urban Legend: Younger people think Onikirimaru is just a legend.
- Walking the Earth: His endless quest to finish off all ogres.
- Who Wants to Live Forever?: Onikirimaru, who actually seeks to end ogres, so he can become human and die.
- Wild Card: Suzuka Gozen, an actual female demon that loves humanity.
