Miscsporadic

While it never made it to anime, Togashi-Sensei did show Kurama and Hiei’s first meeting in a One-Shot called “Two Shot” (???), which I think was published somewhere between Vol. 6 and Vol. 8.

In this one-shot, Hiei’s made his way to the ningenkai following a potential trail for Yukina, as rumors say the fearful Demon Yatsude (who just conveniently happens to live in an abandoned doll factory in Shuichi Minamino’s side of town) has captured and eaten a stray Ice Maiden.

Hiei goes after Yatsude but ends up severely hurt and having to retreat. Fourteen year old Shuuichi, sensing the familiar energy of Hiei,skips school in search for him, and eventually finds him bleeding somewhere secluded. Hiei’s first instinct is to attack the unknown demon, not recognizing Kurama’s aura as weak and human-tainted as it is, and after a short skirmish and only half recognizing the aura before him, he passes out.

Kurama takes him back home to heal his wounds and gives himself permission to check out Hiei’s newest body mod, and also asks Hiei who this “Yukina” he was mumbling about in his sleep is.

Unsure of whether he can really trust this new Kurama after over a decade of him being gone (and with how different his disposition seems to be), Hiei dismisses Yukina as a lead for his tear gem, and tries to brush off Kurama’s persistent offers for help to no avail.

Kurama sticks along, both because he wishes to patch things up with Hiei and because a concerned parent’s phone call seems to indicate a classmate of his has gone missing near the area where Yatsude supposedly lurks.

Hiei and Kurama defeat Yatsude together, and through the following year Kurama coaxes Hiei into keeping in contact with him sporadically, not quite earning his trust back but presenting himself as a reliable ally, should Hiei want his company.

I picture Youko would figure out what Hiei is from his powers (fire demon) + the wrappings he was in (Imiko) + where they found him (somewhere fairly close to the Yuki-onna’s rumored location), but initially he would have absolutely no interest in returning Hiei there, nor even letting Hiei know what he knows.

Youko always struck me as very self-serving and the sort who would enjoy having information on others, and not caring enough about other people’s traumas to go out of his way to address them (it’s just not a very legendary demon bandit thing to do, imo). I also always got the impression Hiei didn’t tell his gang of bandits about wanting to take revenge on the Ice Maidens, which is a HC I usually carry into this AU.

Basically, Hiei doesn’t share his ultimate goal, and while Youko knows what Hiei is and can correctly guess what he wants to do, he offers no help because it doesn’t particularly benefit him.

That’s not to say he doesn’t grow to be invested in Hiei’s well being, in his own detached demonic way, but Hiei’s proclivity to recklessness and getting in fights just for the fun of it is more pressing than Hiei’s potential identity crisis. Youko focuses on curving Hiei’s thirst for fighting and teaching him relevant survival skills (largely in “deliberately put you in measured danger so you can deal with it on your own” ways, with Youko stepping in to help when necessary but making it look like that wasn’t the main goal).

I think the first time they’d actually talk about Ice Maiden Island would be the moment Hiei loses his tear gem by indulging a risky fight with a demon, and Youko finally calls him out on his recklessness, throwing the fact he’s lost his sole prized possesion in his face (by this point Youko would expect Hiei to have more sense). Gives them a chance to fight it out, and Hiei’s goals can be addressed in a way that can be dressed up as beneficial to both parties: Youko just can’t risk having another right hand man who’s going to risk the bandits’ goals for personal gain, so he’ll help Hiei find Ice Maiden Island.

Before that, though, Youko tries to pull of a heist on spirit world and kicks the bucket, and Hiei shows us that no, he didn’t learn a single thing about recklessness, because he goes right on to Shigure when Youko’s gang disbands to get himself the Jagan. He’s going to find his tear gem, the ice maiden village, and Youko, while he’s at it (because he refuses to believe Youko would really let himself be killed).

So the story flows more or less like canon, largely because I like Fox Dad as a passive AU rather than a strong divergence (though I’m certain heavy divergence would be fun).

ACTUAL RELEVANT BIT TO THE QUESTION:

When Hiei and Kurama meet up again, Hiei has already found and visited the Ice Maidens and learned about Yukina (Hiei learns about Yukina from Rui, and was unaware he had a sister before it was so revealed to him; Youko wouldn’t have had a way to guess Hiei had a twin sister, or at least I see no mention of Imikos necessarily having to be half of a twin pair).

Last time Hiei admitted his goal of looking for something importnat to Youko the bastard went and died, so he doesn’t tell Kurama about having a twin sister he’s trying to find when they meet again in the human realm. Hiei merely lets him believe he’s still only hunting for his tear gem, to which Kurama offers his help (Hiei helpfully offers, “try not to die this time”).

The ruse is up when they have to rescue her from Tarukane, but since Hiei doesn’t want/can’t tell Yukina he’s her brother, there’s not much Kurama can do anyway, except looking after her and teasing Hiei about their relationship.

….Which Kurama already canonically does! ◉‿◉

(Go to 0:50; if you haven’t seen the english dub for YYH I hope this’ll sway you into it.)

Or that time they were all playing cards in the Dark Tournament hotel room and Kurama teased Hiei about why’s he not joining them?

Kurama as he interacts with everyone on Team Urameshi is very doting and thoughtful, and of course for Fox Dad I’d like to see him be extra thoughtful of Yukina, but I think what he canonically acts like towards her would already be pretty accurate. Kind and thoughtful, but not overly cloying or too obvious about considering himself a guardian figure to her just because there’s teasing and then there’s “give away Hiei’s secret without his consent.”

(Have I mentioned how easy it is to re-interpret canon Kurama/Hiei interactions into Fox Dad and how much I love that? Because I do. Kurama’s such a Mom Friend.)

Sorry again for getting so long-winded! And I’ll throw in a reminder of “this is just a silly AU and if you want to grab it and do your own thing with it, feel free”!

Want to picture Youko is more involved in Hiei’s plight, so he takes him to the Ice Maiden Island and adopts Yukina before she has a chance to wander off on her own in search for Hiei? Let that foxy grampa raise himself twins!

Want Kurama to appoint himself Yukina’s guardian to make up for his abandonment of Hiei and be attentive to her (in obviously parental ways which Kuwabara nonetheless perceives as potential rivalry, despite Yukina treating Kurama like a respected elder)? Go for it!