''Ogre Slayer'' (鬼切丸 ''Onikirimaru'') is a manga series created by Kei Kusunoki. The manga has been adapted into a 4 episode OAV.

''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:

* AbsurdlySharpBlade: Onikirimaru
* BornLucky: One of the Ogre hosts has escaped many accidents unhurt, turns out it's because the ogre is just protecting it's host.
* CoolSword: Onikirimaru, one of the few things that can surely kill an ogre.
* DarkerAndEdgier: The [=OVA=] compared to the manga.
* EmpathicWeapon: Onikirimaru won't hurt the nameless hero as it's actually part of him.
* EquivalentExchange: 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.
* {{Gorn}}: Borders in {{Narm}} at times.
* HumansAreBastards
* HunterOfHisOwnKind
* IJustWantToBeNormal: 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.
* KeepCirculatingTheTapes: The manga only had two volumes translated into English by VIZ. Also, while all four O[=V=]As were dubbed, the VHS' have been long out of print and have never been released to DVD. Thankfully, the first two O[=V=]As have been put on Youtube and the other two should be online soon as well.
* KickTheDog: Ryoko, the maid, get's constantly abused by the rich family she serves.
* NotSoDifferent: Onikirimaru and Ryoko; conversely, some humans and the ogres.
* OlderThanTheyLook: Onikirimaru.
* OnlyKnownByTheirNickname: The nameless hero is most commonly known as Onikirimaru, which is the name of his sword.
** IAmNotShazam
* PetTheDog: Onikirimaru to Ryoko, the maid.
* ReallySevenHundredYearsOld: Onikirimaru.
* SealedEvilInACan: Some ogres start the stories this way; Onikirimaru unseals them himself so they can be properly slain.
* StepfordSmiler: Ryoko, and Onikirimaru.
* TakesOneToKillOne: He is a pure blood ogre, despite his looks.
* TallDarkAndHandsome: Onikirimaru.
** TallDarkAndSnarky
* TooDumbToLive: Some of the ogre victims.
* UrbanLegend: Younger people think Onikirimaru is just a legend.
* WalkingTheEarth: His endless quest to finish off all ogres.
* WhoWantsToLiveForever: Onikirimaru