Kairanger

Kairanger is the family ship between Kai Satou and Rio Ranger from the Your Turn To Die fandom.

Kai's past episode
During another day of harsh training as a child, Kai is told by his father Gashu that once he completes his tasks, he will be introduced to someone. Kai is curious who it is, but Gashu does not tell him. After finishing, Kai meets Sei. Gashu explains that the two have undergone the same training, are about the same age, and are "similarly excellent". Sei is doubtful that Kai is excellent as Gashu says, irritating Kai. Gashu tells them to settle down, since as of now the two are siblings. Kai thinks that must mean Sei will be his little brother or sister, to which Sei insists that Kai call him "big brudder".

The two are arranged to train together as sort of a competition. Kai doesn't like that Sei has been brought into the family, wondering if it happened because Gashu is not satisfied with him.

While training, Sei continues to call Kai "bastard", making Kai demand he call him by his name. Sei agrees to if Kai calls him "big brudder", which Kai begrudgingly does. Sei pets Kai, angering him further, and he pushes Sei harshly. Sei takes this as an invitation to show him discipline by fighting him. Sei easily downs Kai, remarks that if they're going to be killers, they have to be strong, and then leaves. Kai decides he can't lose to someone like him. At dessert, Kai is forced into admitting defeat to his "big brudder".

The next day, Kai insists for more training with his instructor, and hearing that, Sei goes along with it too. They continue this way, constantly pushing themselves because the other won't quit either. After being visited by Gashu, Kai addresses that Sei hasn't been speaking to their father with proper respect. Sei was never told to correct it though, and he thinks Kai is "scrambling for ways to score points" when it doesn't matter. Kai becomes angry, since Sei was an outsider, and yet he seems more loved by Gashu. Sei sees that he has to fight Kai to get him to understand, and once again wins over him.

Sei remarks that Kai is so weak, but he has to be strong, because he's just a tool for Kai to use as a means to get stronger. Sei cries, because he knows he was only brought in for that purpose, and not to really be family. Sei shares that his real dad is dead, and he hates all the organization stuff. Kai apologizes to Sei. He feels like he was hearing Sei's real voice for the first time, and empathizes with him, because Sei wanted recognition for never losing, while he wanted recognition for winning. Kai tells Sei that because Gashu's kind moments are very few, he didn't want them to go to someone other than himself. Kai realizes that perhaps they were both starved for affection.

Following that, Kai and Sei become on much better terms. On one day of training, they banter over winning over the other, but it's in a friendly nature. Kai happily declares that they best give their next task their all.

Gashu is visited by a woman who says only one of his sons need to live since they only need one first-class assassin trained for Asunaro. Gashu is enraged at the suggestion that he have his sons kill each other, but he reluctantly goes through with it anyway.

Kai and Sei are put on an island with other child assassins who are all trying to kill each other. Kai is taken aback when Sei nonchalantly says he's already killed two people. Sei catches on that Kai is trying to suggest they work together, but doesn't think it'll work out. Kai says there's no reason to take part in the assasin business, but Sei tells him that since they were trained to do just that, if they weren't able to, their lives would have no value. Sei says that if Kai is so torn up over it, he'll kill him so he won't have to decide. It comes down to a real fight with Sei. No matter what Sei tries to attack, Kai is able to block it, and ultimately, Kai downs Sei. Kai doesn't want to kill Sei, though. Sei says that not that long ago, Gashu started treating them much more coldly, and started teaching Kai alone, so that's why he can't beat him anymore. Sei insists that he's still not inferior in talent and effort, so Kai should stop looking down on him.

All of a sudden, Kai shouts for Sei to watch out. Out of nowhere, another boy assassin stabs Sei from the back. Kai readies his knife, but Sei already has his in hand and slashes the boy's neck. The wound is horrible, but Kai wants to find a way to treat it. Sei asks Kai to kill him instead, reasoning that it wouldn't feel as lonely that way. Kai just embraces Sei in his arms and witnesses his death.

Thereafter, even despite his continued training, Kai was unable to kill anyone as he kept remembering the sight of Sei's death. As an adult, Kai wonders that if he had been aware of his foolishness from the beginning, such a tragedy would not have happened. Mr. Chidouin thinks that's wrong, rather that Sei protected him so he didn't have to stain his hands with blood, and is the reason he's so kind where he is now.

Your Turn To Die
About three years before the Death Game, Gashu created a doll in Sei's likeness but slightly more grown up, called Rio Ranger. The relationship of Kai and Ranger within Asunaro is unknown, but regardless, Kai died in the Death Game before being able to meet Ranger on the third floor. After Kai's death, Ranger took Kai's apron to wear around his waist.

Quotes
"...Ahah. Sure enough... you recognized this thing around my waist? It feels good, y'know... Feels like it's full of the dead's regrets... The regrets of Kai Satou... That foolish man whose rebellion destroyed him."

- Ranger when it's pointed out that he's wearing Kai's apron

Fanon
With both Kai and Ranger recognizing Gashu as their father, they were linked as brothers by the fandom even despite the fact that Ranger is a doll. This fact prompted ideas on what would happen should Kai have reached the third floor. Some think Kai would have protected Ranger when Gashu shot him, or that Ranger would have protected Kai from dying as a non-candidate with the Sacrifice card.

With the release of Kai's mini-episode, yet more ideas arose over the fact that if Kai did make it to the third floor, he would be able to meet his dead brother again after so many years. However, that also poses the question of whether Kai would want to see Ranger due his traumatic memory of his death. On top of that, whether or not Ranger was given memories of his time with Kai and would recognize him is unknown. It would be especially heartbreaking if Kai recognized Ranger, but not the other way around. Kai doesn't mention Ranger in his laptop anywhere, which may be because they don't know each other. Others think that it's because Ranger's existence pains Kai too much, so he doesn't talk about it.

AUs including the two are mainly those where Kai and Ranger live together as family. Some take place pre-Death Game, while others take place in a no-Death Game AU.

Fandom
FAN FICTION