The Ortho Siblings (オロソ()(きょう)(だい)()()()()()()(), Oroso Kyōdai) were a pair of Chimera Ant siblings who resided in an Underground Lake in the Republic of East Gorteau.[1]


They were humanoids and had features of aquatic animals. Both of them had scales covering their legs as well as webbed feet. Scales also covered the older brother's arms while the sister's arms were left bare; though in the 2011 anime adaptation, there is no such distinction and both of them had scales covering their arms.


The brother was quite sadistic, wondering why Killua wasn't screaming,[2] and expressing that he wanted Killua to die in fear.[3] The sister was very trusting of her brother, and was proud of his abilities. They both loved each other very much and their confidence spawned from it.[2] However, once defeated and decapitated by Killua, they lost all respect for each other and began bickering.[4]


Chimera Ant arc

Ortho siblings base

The siblings playing their dart game inside their base

After Remora successfully attaches the "Bar Double Bull" badge on Killua, the Ortho siblings are revealed and the brother begins their conjoined Nen ability Darts De Darts.[1] After Killua washes ashore, a sound goes off in his head; he's immediately hit with two large fish like darts on his left hand and chest and realizes his entire body has become a dartboard. The brother then telepathically speaks to Killua and inquires if he has any clue of what's happening to him. In the siblings base, the brother removes the darts, off the dartboard and re-throws the darts, piercing Killua's right shoulder and both of his thighs. As the brother pierces more of Killua's body with the "fish darts", he asks if he's figured out what kind of attack he's being struck with. Killua manages to get near and look into a nearby pool of water to deduce it's a game of darts and the brother confirms it.[2]

The brother then explains to Killua that he can't do anything against his ability even if he knows it because his darts only materialize when in contact with the target and after a dart pierces Killua's left shoulder, he details it was worth 54 points and the targets on his board are linked to various parts of his body. The brother pierces Killua's elbow worth 27 points, the back of his right hand worth 18 points, making a total of 99 points. Back at the siblings base as the brother continues to rack up points, the sister, seated upon a bar stool, praises him. The brother then boasts that the two of them are invincible and the sister claims it's because they're bound by a strong sense of trust.[2] With the game close to the end, the sister asks her brother if they should tell Killua about it. However the brother rejects the idea to torture him further so he could have better concentration playing and continues to throw a dart onto the board hitting Killua's left arm, chest and right leg.[3]

On the final turn, the brother hits Killua's left ear for 18 points, the right calf for 7 points, and finally the forehead for 20 points. This ends the game and the siblings win, celebrating with their special clap together. The siblings then leave their base to check the body of Killua who lies on the ground with a dart sticking out of his forehead. The brother contacts Flutter and informs him of their accomplishments. Flutter praises their actions and informs the siblings he'll inform Leol and convince him to have them promoted to Assistant Squadron Leaders. The siblings celebrate the fact they'll become higher ranked and then start to perform their special clap again only to have their heads severed by Killua at the end. The brother demands to know how Killua managed to survive when a dart is sticking out of his head. Killua pulls the dart from his head reveals he used a suction cup from an octopus.[3]

Killua beats the Ortho Siblings

The Ortho siblings killed by Killua

The brother then asks how Killua was able to pull off such a trick when his darts are impossible to dodge. Killua explains he didn't dodge the final dart. After figuring out the final dart was aimed at his head, he cultivated a new Nen ability named Godspeed to optimize his reaction speed, allowing him to stop the dart the moment it touches his skin. The brother inquires about Killua's darting experience. Killua replies that at age six, he mastered the game.[3] The siblings then bicker among each other and when Ikalgo rescues the incapacitated Killua, the siblings try to convince him to save them instead, but only anger him for calling him an octopus.[4]

Abilities & Powers

Being Chimera Ants with the genes of fish, the Ortho siblings could breathe underwater and were immune to water pressure to a certain degree. Like other Chimera Ants, they seem to feel no pain even if mutilated, as their heads continued to bicker after being severed. The brother was exceptional at throwing darts.


The Ortho siblings' combine their Conjuration skills in a single Nen ability, which means they are at least capable of performing Hatsu.

The Ortho Siblings' Nen Abilities
Type: Conjuration Darts De Darts (死亡遊戯(ダツDEダーツ) Death Games)
Ortho siblings badge

Ortho siblings base

Ortho Siblings nen on Killua
The Ortho Siblings' Nen abilities work in conjunction: the sister conjures a tag that, when placed on someone, will link her brother's conjured dart board to the target. The tag cannot be removed until the game ends, not even by themselves. The brother then throws darts at his board, and when they hit their mark, a sharp fish-like dart made from his aura is conjured and pierces the target's body in a place that depends on where the darts hit the board. The fish darts are impossible to avoid, since they don't physically exist until they touch the target's body. However, the Siblings run a considerable risk playing the game, because as a condition, if the older brother misses the last shot to end the game, all the damage accumulated on the target until that point will be carried over to themselves.[2]


  • Chimera Ant arc:
    • Ortho Siblings and Remora vs. Killua Zoldyck[1][2][3]


  • The relative age between the siblings is distinguishable especially due to the kanji used for them, (きょう)(だい)()()()()()()()() (kyōdai, lit. "older brother and younger sister"), making it clear that he (兄, "elder brother") is the older sibling and she (妹, "younger sister") is the younger one.
    • On the website for the 2011 anime adaptation, the Ortho brother is referred to as "オロソ兄" and the Ortho sister as "オロソ妹".[5]
  • It is unclear why they place emphasis on being siblings since all Chimera Ants were born from the same mother. Although there is an implied age difference between the two of them, it is possible they were hatched from the same egg, that they were born from the same genetic material, or that the humans or animals from which they were born were siblings.

Intertextuality and References

  • The dart game they were playing was a 01-501 game. The game starts with 501 points and the goal is to reach zero.
  • Their Nen ability is likely based on Kaname Hagiri, an antagonist from YuYu Hakusho, another manga created by Yoshihiro Togashi. Hagiri was capable of marking his victims with targets and shooting projectiles that would automatically aim for those targets.

Translations around the World

Language Name
The Arab world Flag Arabic الإخوة أورثو
France Flag French Oroso


  1. 1.0 1.1 1.2 Hunter × Hunter - Volume 23, Chapter 238
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Hunter × Hunter - Volume 23, Chapter 239
  3. 3.0 3.1 3.2 3.3 3.4 Hunter × Hunter - Volume 23, Chapter 240
  4. 4.0 4.1 Hunter × Hunter - Volume 23, Chapter 241
  5. Nippon TV - HUNTER×HUNTER - Chimera Ant: characters page


  1. Although their rank was never stated, Remora's use of a honorific (in Chapter 238) to address the brother suggests that they are Captains.


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Chimera Ants
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(Peons & Drudges)
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Leader Welfin
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Officers BokiGorillaGun-toting AntPikeSmall Beetle
Drudges & Peons Pell
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