100 kg220 lb
Each of Killua’s yo-yos weighs 50 kg (110 lb), so the pair comes to 100 kg (220 lb). Killua gives the figure himself in chapter 178 of the Hunter x Hunter manga, fighting Sub on Greed Island, and both anime versions repeat it. They are made of a special alloy from his brother Milluki.
The number is official and comes straight from the story. In chapter 178 (volume 18), Killua takes on the Bomber Sub alone and tests his new weapon on him. His first swing misses and knocks down a tree. When Sub asks what the thing is made of, Killua says it is a custom alloy from his brother Milluki and weighs around 50 kg.
Killua first shows the yo-yos to Biscuit in chapter 150, when the group starts preparing for the Bombers, and tells her he plans to use them with his Nen. They are not part of the Hunter Exam or Heavens Arena arcs: he gets them from Milluki after leaving Greed Island to retake the exam.
Our header number, 100 kg, is simply two times 50 kg, because Killua carries and fights with both. The second one is the surprise in the Sub fight: Sub knocks the first yo-yo away, only to be hit in the back of the head by the other.
All three versions give the same weight. The 1999 series covers the fight in the Greed Island Final OVA, episode 11 (episode 89 overall, “Bisky × Killua × New Special Attack”, released in 2004), where Killua says the yo-yo is a special metal weighing 50 kg. The 2011 series has it in episode 73, “Insanity × And × Sanity”, again at 50 kg. The only nuance is the manga’s “around”.
What changes is the look. In the manga the yo-yos carry a six-pointed star, while the 1999 OVAs swap it for a five-pointed star or pentagram. The anime colors them purple, navy or dark green with yellow stars. The manga is not even consistent about the string, which is usually drawn as wire rope but sometimes as a chain.
Not at that size. Killua’s yo-yos are drawn roughly palm-sized and fit in his pockets. Take a generous cylinder 7 cm wide and 4 cm thick: that is π × 3.5 × 3.5 × 4, about 154 cm³. Osmium, the densest stable element at 22.59 g/cm³, would make it about 3.5 kg. To reach 50 kg, the alloy would need a density of about 325 g/cm³, some 14 times that of osmium.
Turned around, a 50 kg yo-yo of ordinary steel (about 7.85 g/cm³) needs about 6,370 cm³ of metal. That is a disc roughly 25 cm across and 13 cm thick, closer to a small car wheel than a toy. Our calculation, not canon, but it shows why the yo-yos are a fantasy object.
Heavy gear is normal in Killua’s family. Each panel of the first door of the Testing Gate, the entrance to the Zoldyck estate, weighs 2 tons, and every set of doors after that doubles. Before learning Nen, Killua opens up to the third set, 16 tons (chapter 39). After the Chimera Ant arc he opens the fifth set, 64 tons (chapter 321).
Even the servants’ house is a workout. In the English translation of chapter 40 its doors weigh 440 lb (about 200 kg) each, and the slippers and teacups 44 lb (about 20 kg) apiece. Next to that, a 50 kg yo-yo is just another piece of family equipment.
For scale, the official databook gives Killua a height of 158 cm and a weight of 45 kg (99 lb). The pair of yo-yos weighs more than twice as much as he does. The set does not stay whole: in chapter 293, Palm, reborn as a Chimera Ant, smashes one of them with a single blow.
Each yo-yo weighs about 110 lb (50 kg), so the pair is about 220 lb (100 kg).
A special metal alloy that is never named, made for him by his brother Milluki. It conducts electricity well, so Killua can send his Nen lightning through the yo-yos, and the polished surface works as a mirror for looking around corners.
He first shows them in chapter 150 and first fights with them in chapter 178, against Sub. In the 2011 anime that fight is episode 73; in the 1999 version it is episode 11 of the Greed Island Final OVA.
The Testing Gate has seven sets of doors. Each panel of the first weighs 2 tons and the weight doubles with every set, up to 256 tons for the seventh. Killua opened up to 16 tons as a child and 64 tons later in the series.
The official databook lists Killua at 45 kg (99 lb) and 158 cm. His two yo-yos together outweigh him by more than double.
Last checked October 3, 2026.
