If no one is aware of what he’s talking about, Killua is mentioning here some cards revolving around naked females.
There are at least four cards in the whole Greed Island game which take the humanoid form of an NPC girl.
These girls are as follows:
A funny fact about these specific cards is that the covers all depict the girls either half naked or fully exposed. Numbers 46 and 47 of these cards (“Gold Dust Girl” and “Sleeping Girl”) are the ones who are shown fully naked while numbers 18 and 48 (“Aromatherapy Girl” and “Imp’s Wink”) are presented half nude by hiding their upper body. They are also all A rank and have to be collected to finish the game.
What’s interesting but odd about the way that these cards look, is the fact that the girls don’t have to be bare to activate their power since their ability has no connection to being unclothed in the first place.
For more information on the background of these girls, here are each of their abilities in a summary:
Number 18: This card summons forth a magical NPC Imp. When this Imp winks at a player, it gives them the most amazing ecstatic feeling. She can appear multiple times within proximity to the caster. Be warned as this feeling can get addictive.
Number 46: This card is the Gold Dust Girl NPC in card form. She releases golden dust from her body daily, hence her name. One bath a day will give you around 500 Grams worth of gold. She is located in a room four floors below ground and guarded by various traps. She's very shy and quiet.
Number 47: This card is the Sleeping Girl NPC in card form. When gained, it allows the user to go a whole 24 hours without the need to sleep. Instead, your sleep need is fulfilled by the girl. She sleeps soundly in your stead while you are free to use your extra 12 hours.
Number 48: This is the Aromatherapy Girl NPC in card form. When gained, this girl emits the most comfortable and pleasant aroma for the caster. When she is by the player's side, they will be completely free of any stress. This also allows for a calm mind, enabling the player to think more clearly.
Now that we have been reminded of what these abilities can do, we can safely agree that the only card to have a rational reason for being naked would have to be Number 18 “Imp’s Wink”. Since her ability is all about giving the player an “ecstatic feeling”, her exposed body should somewhat have a role in helping the player feel good.
So then what does this tell us for the rest of these cards?
Number 46, Number 47 and Number 48.
These three cards must’ve been what Killua was referencing in his “girl series” due to where they all stand in the game.
Numbers 46, 47 and 48 all follow up on each other in chronological order. Not only that, but even their names have the same structure. They all start with the ability of the card and follow up with the word “Girl”.
There are no other cards like these three. This is why “Imp’s Wink” cannot be considered as one of the cards of “the Girl Series” since the number of the card doesn’t stand before 46, between, or after 48. It doesn’t follow the same name system as the other three as well.
So this is where things get more peculiar.
There is no actual group name to address this trio set of cards. They are just cards that happen to have the same style only that each is a bit different than the other.
The fact that Killua called them “the Girl series” when there was no reason to, makes me think that Killua voluntarily looked into what their abilities were all about before trying to win them all.
And this is an excruciatingly important detail to note.
During that time, Gon, Bisky and Killua had to collect as many cards as possible to complete the binder section that was essential for them to complete the game. The boys were also using the game as some form of ground test to see how far their training with Bisky improved their abilities. This means that they weren’t focusing on learning too much about the cards and were much too into collecting them than anything else. This also means that Killua wasn’t supposed to learn about them. He deliberately decided to look into these girl cards!
This is a surprising but cute detail to notice in Killua because he really just did waste some of his time to learn more about what these three cards were capable of. Not only that, but it looks like he seems to have also really liked them a whole lot to the point where he made up a group name for them!
Look at how boisterous he is too when finding one of them. Because of his posture and expression, he almost sounds like he’s stating a fact when calling them “the Girl series” as if these cards were supposed to be called this way.
Granted, we are not quite sure if he gave some group names to other cards that seemed to share some similarities between each other like how he did with these three. Since the trio’s hunt for the essential cards wasn’t entirely shown in the manga and anime, we cannot entirely confirm that these three cards were the only ones to have been given a group name by him.
But why would Killua even look into these cards in the first place? If these cards are the only ones who have been given a group name by him, why did he even look into them to begin with? What made him so interested in them for him to invest his time on them?
The answer might be slightly stupidly accurate for him.
I believe that Killua looked into these specific cards because he could have been intrigued by the reason as to why each of the girls was shown naked on their respective covers.
Killua is a rather intelligent boy when it comes to situations where he needs to quickly solve problems by just relying on one specific item. When he must’ve seen the cards’ titles, he already knew what they could've been all about. He probably thought that number 46 was a card able to give you gold particles in a specific way, number 47 made him speculate that there was some kind of “sleep exchange” going on with the player and the card, and as for number 48, Killua could have figured out the ability by a single glance at its card title since it‘s the only one between the three that is pretty descriptive by just the name alone.
This means, that Killua must’ve looked into these cards for the exposed bodies, wondering why they had to look this way in their images.
Whether this was intentional or not, it would have been pretty hard to believe that Killua, a preteen who’s starting to enter puberty, would’ve only tried looking into these cards out of pure intentions.
What he must’ve first noticed about these cards was the fact that since their names, which were describing their ability, did not match with why they would have to be naked in the first place, this left Killua a bit confused but curious enough to take a look at what their cards might’ve been all about entirely. (So far, he is now aware that the only card between the three who has a reason to be naked on a daily basis, is number 46 “Gold Dust Girl”. I bet he also most likely wanted to check out “Imp’s Wink”‘s ability information for “educational purposes”.)
Since we now know the (rather perverted) most relevant reason as to why he must’ve looked into these three cards specifically, there is only one question left at the back of our minds that could wrap up this whole scene in a jiffy:
How did Killua learn about these cards before winning them?
This is a rather interesting but confusing question to think about for many numerous reasons.
1) The player’s binder can only place cards of the same number in the restricted slots. There are no other hints as to what any of the cards you have to acquire could be about. The binder only gives out the number of the card.
2) The same goes for the player’s 45 free slots. The binder itself cannot even show you what cards outside of the restricted slots you can win.
We are aware that there is no official name group for these three humanoid NPC cards and we also know that these three look similar to one another. So Killua, at some point, must’ve been able to find out about each one of them on his own before starting winning them. We know he is aware of how many there are given the fact that he said, “Got the first of the Girl series!”.
But even though there seems to be no possible way for him to find out about these cards without already being informed of them, the only plausible explanation for this is that he might’ve simply been observing other players win these cards. This could be true and possible for him to do so since we, the audience, don’t get to see the trio’s full process in collecting all of the restricted cards. Therefore, we wouldn’t have been able to watch Killua learn about these three cards from other players who already got them.
In conclusion, I feel like there are lots of people who disregard this small scene and think it’s just some plain words said by Killua that don’t mean anything when in actuality, they give out a huge unexplored side of his personality that isn’t usually fleshed out very often.
Which would be his perverted and shameful side. Surprisingly, this small scene seems to have explored it a little bit.
(1999 Killua doesn’t count in this so we can’t say that this side of him has already been widely explored in the 1999 version since that interpretation of hxh isn’t canon.)
PS: The 2011 anime version for this same scene made Killua simply say:
Instead of saying “Got the first of the Girl series!”. I find that change to be very odd. Odd because it is just a simple line that shouldn’t have to have been completely changed in the first place.
PPS: There’s also another translation made for the online manga that has Killua say:
He says the same thing as his anime counterpart but we can tell that this is simply a mistranslation as well as an untrustworthy site given the fact that Gon says right after: “She’s in the F category in the binder.”
Gon’s claim is completely false here for two reasons:
A) Gold Dust Girl’s bodyguard is actually the one that belongs in the F category. Not her. You can tell that she’s from the A category if you read her card’s information.
B) Gon isn’t holding the Gold Dust Girl card. He’s holding the bodyguard’s card. The one who’s holding the A rank Gold Dust Girl card is Killua.
What is especially weird about this online translation is the fact that almost all hxh online manga sites have done the same mistake making these inconsistencies. As I'm currently writing this, only one site so far has managed not to repeat that same weirdly common error.
When we take a look at what the physical copy of the manga shows, it keeps the real translation of Killua saying that girl sentence. And the same could be said with other languages.
As an example, if we take the English, Brazilian Portuguese and Italian, you’ll come to find out that the majority shows Killua saying the same line no matter the language.
(The Italian version doesn’t say it however. Some languages like Italian may have some of the parts right. It’s only the translation process that may get trickier to let them keep the original lines which could lead the Italian language to make the decision to not make Killua say it.)
PPPS: I should also mention that unlike the 2011 version, the 1999 version stays true to the manga for this scene and has Killua say:
