Subaru first met Kamui when he was at his lowest point--he had just been betrayed and nearly murdered by his best friend, plus witnessed the grisly death of his other best friend. That was one hell of a Monday. In his distress, Kamui closes himself off from the world and goes comatose--alive and awake, but completely gone in any functional sense. Subaru is familiar with this state considering he had experienced a similar one nearly nine years previously when a similar traumatic incident occurred. At the time, Seishirou, a man he had counted on as a friend and grown to love, revealed that he was an assassin who had marked Subaru as his prey when Subaru was only a child. He was the head of a clan of onmyouji that exists in opposition to the Sumeragi clan and had been lying to Subaru the entire time they were friends. Subaru went into an emotional coma and when he finally came out of it because of the shock of Hokuto's death, he realized that Seishirou had killed her.
Having endured such misery, Subaru was uniquely positioned to understand and sympathize with Kamui, yet was also experienced enough to know that staying in that state would probably not make the younger man happy. Using a spell known only to the Sumeragi clan, he enters Kamui's consciousness, battling his defenses as he sinks deeper in, and ultimately convinces him to return to the living world. He does so not by assuring him that everything will get better or invoking an obligation to save humanity regardless of his personal suffering; he simply states that Kamui cannot change anything if he does not face the world. In reality, that is probably the only argument that had a chance of convincing Kamui to wake up.
Due most likely to their similar personalities and situations, Subaru and Kamui understand each other quite well. When he is hurt protecting Kamui, Subaru knows that Kamui will torture himself with guilt over the injury and tries to convince him not to do so. When Seishirou dies in Subaru's arms, Kamui knows that he probably wanted to die there as well, but decides to rescue him anyway. Subaru, after spending some time with Dark Kamui, comes to understand Kamui's true wish and urges him to realize it before it is too late. They both have wishes that they know will make others unhappy, but they pursue those wishes anyway, and neither reproaches the other for doing so.
One thing is very clear when looking at Kamui's relationships, both before and after his decision to join the Dragons of Heaven--and that is that Kamui was horribly starved for affection and trust. Even though the Dragons of Heaven clearly care about him, he struggles to call them friends, because he is unsure of their relationship. It takes even Sorata, one of the friendliest guys in the entire series, all of his charm and determination to finally gain Kamui's trust. Subaru literally enters his mind and risks being killed in order to form a connection with him. The only thing that keeps Kamui connected to the Earth and even his own life are the connections he shares with other people, and both connections and people, as the series clearly demonstrates, are both fragile and precious things.
For his part, Subaru seems to like Kamui as well. It could be that he simply helps Kamui because he is the key to protecting the Earth, but that would only explain why he helps him in battle. There was no reason for him, for example, to help Kamui tie his tie when his hand was injured unless he actually cared enough about him to want to do so. Furthermore, it would be extremely uncharacteristic of Subaru to use another person in that way. Subaru has always been compassionate and caring, and his concern for Kamui shows that his relationship with Seishirou may have damaged him in some ways, but he remains fundamentally kindhearted. Even though Subaru ultimately leaves the Dragons of Heaven for the Dragons of Earth to take Seishirou's place, Dark Kamui observes, "You seem to care about Kamui. Not me… the other one." (vol 18) If anybody would know something like that, it would be Dark Kamui.
Probably the first member of the Dragons of Heaven to make a real connection with Kamui was Sorata, a cheerful young monk from Mount Kouya. Perhaps the main reason that he is able to cope with Kamui’s incredibly hostile exterior is that he is completely the opposite in nature—open, honest, and more than a little inclined towards frivolity. He’s ultimately a people person with a keen gift of insight and perception, which is an interesting counterpoint to Kamui who has trouble understanding people. Although he is about Kamui’s age, he still acts more like a big brother towards Kamui than anything else, even while Kamui is at his most unreceptive. Sorata’s gentle yet consistent companionship plays a major role in Kamui’s ultimate personality transformation from raving jerkass back to someone a little more sympathetic.
Although his mission as a Dragon of Heaven is to protect Kamui with his life, his ultimate fate will be to die for a woman. Sorata was taken from his family while he was still very young so he could be trained at the Buddhist monastery in order to fulfill his destiny in the coming years. Although he enjoyed his life as a monk, his only memory of his mother is the tears that were streaming down her cheek as she left him there. This memory haunts him and inspires his desire to never see another woman a cry, which is why he accepts his fate so readily.
Although Sorata had been observing Kamui before this, they actually meet in the second volume after Sorata fights a battle with Yuuto (a Dragon of Earth) to decide who will get to talk with him first. Sorata, who possesses considerable knowledge of various occult organizations in addition to knowledge about the “Promised Day”, offers Kamui knowledge about his family. For a while, the relationship remains rather rocky and uneven, given Kamui’s sudden fits of violent rage, but Sorata persists and eventually the two become fairly close friends. Although Kanoe quickly figures out that Kotori and Fuuma are Kamui’s weaknesses, Sorata also observes how much he cares about them and even suggests putting them under surveillance in order to keep them safe. When Kotori dies, he mourns the fact that, as Kamui’s protector, he was unable to do anything. “I'm sorry. I was a bigmouth and said, ‘If anything happens to you, I will throw my body in the way and help you somehow.’ It turns out I couldn't do anything” (vol 9). He even asks if he can pray for the young girl who died so tragically.
In a way, Sorata is more of a leader of the Dragons of Heaven than Kamui, who often appears completely lost. Certainly Sorata tends to take the lead a bit more often, especially by directing the others to split up into teams. Even in their personal life, Sorata and the three other school age Seals share a dorm suite at CLAMP Campus and he appears to be the de facto big brother of the group. In one scene, he holds his hand up to Kamui’s head while holding the other up to his own in order to see if Kamui is running a temperature. The scene is so domestic that it seems rather funny in a story that is mostly about the world ending.
Although Kamui never comments on Sorata’s leadership, it appears that he appreciates Sorata and trusts him as a close ally. Perhaps the only other person he trusts as much as Sorata is Subaru, but that might be because of their shared experiences—namely having a loved one murder another loved one. Subaru gained Kamui’s trust by going deep within Kamui’s heart following his greatest moment of torment. Sorata had to slowly gain Kamui’s trust through cheerful personality and steadfast loyalty. Once Subaru is gone, it is Sorata he turns to when he suspects that something is wrong with Hinoto and he trusts him to find out what is going on.
Sorata, in some ways, acts as a point of contrast to Kamui, not only in personality, but also in terms of accepting his destiny. Kamui, for the most part, remains ambivalent about his role in the final days, if not, as in the beginning, completely set against any involvement. Despite facing the crushing loss of his mother when he was a young child, Sorata on the other hand, has gladly embraced his role in the End of the World and his destiny, though with one little twist—he will choose the girl for whom he will die. It is a strange balance of choice and destiny that characterizes X/1999’s take on the duality of these two ideas as well as the concept of duality in general.
For Sorata, and many other characters, Kamui represents a purpose. He could easily have resented Kamui and blamed him for the fact that he was ripped away from his mother when he was very young. Instead Sorata, ever the optimist, sees his fate, and his relationship with Kamui, as an opportunity to find the woman he will love and for whom he will eventually die. Even if he dies in this conflict, which I believes he will, his life has not been lived in vain. He has faith that losing his relationship with his mother will be worth it in the end—that Kamui, and the woman he loves, will be worth that sacrifice.
Sorata has a powerful impact on Kamui’s character. He is one of the few people who can actually communicate with Kamui in the beginning and he is one of the people who understand Kamui the clearest. Because of Sorata’s influence, he slowly begins to show his softer side. Kamui, who has been so starved for friendship for most of his life, finds a close friend and confidant in Sorata, who, unlike Fuuma, will not betray him. Kamui may have eventually choose to be a Dragon of Heaven at some point because of his relationship with Fuuma and Kotori, but Sorata and his kind spirit certainly made it easier.
While technically Arashi is the first Dragon of Heaven Kamui meets, she is not the person with whom he makes his first major connection. In fact their first encounter was a fight in which Arashi had to protect a comrade from Kamui’s wrath or else Kamui could have killed him. Although Arashi is loyal to Kamui from the start and seeks to serve him to the best of her abilities, she seems ill equipped to actually deal with him. To some extent, this might be because Kamui and Arashi share similar characteristics, specifically the fact that neither is particularly sociable or adept at dealing with other people. Also both have faced major tragedies—the death of their mothers—and attempt to cope by suppressing their true emotions and acting indifferent (though Arashi manages this more effectively than Kamui). She is a powerful ally and someone Kamui eventually comes to care about, but their relationship is still limited.
When Arashi and Kamui first meet, Kamui isn’t particularly interested in his “destiny” or the future of mankind and seems determined to live only for himself. After their first contact, Arashi recognizes his incredible power, but she appears to be troubled by his violent reaction to Daisuke and his disregard for civilians. Still, she continues to an alliance with him apparently out of a sense of duty to her destiny and faith in the visions of Hinoto the Dreamseer. Initially Kamui regards Arashi as an enemy since she keeps him from “his prey” (meaning Daisuke) and when she approaches him again, he prepares to fight her once more. After Sorata befriends Kamui, he is able to bridge the gap between the two with his cheerful demeanor and pleasant personality and they develop a cordial relationship. She is present during Kotori’s murder and worries about the fate of the world if Kamui decides to remain lost in his own mind after he breaks down.
Once Kamui’s temper calms and his aggressive personality slips away following the death of Kotori, he begins to care about Arashi as a friend in a general sense, which she reciprocates. The four younger Seals move into a suite at the Clamp Campus and become a kind of surrogate family unit, perhaps even a Nakama, with Sorata as the binding, quasi-father figure. She cares about him and his well being, particularly after the death of Kotori and she comes to see him as more than just a figure head in the battle for the end of the world. Kamui also worries about her, particularly after she disappears after her night with Sorata. Still, Kamui and Arashi have very little one-on-one interaction, though Kamui is the person who brings Arashi to her senses after Sorata is badly hurt protecting her and she begins to break down.
Yuzuriha is the youngest member of the group and next happens to be Kamui. That may be the reason why their relationship becomes deeper like the others. Not only is Yuzuriha the youngest Dragon of Heaven, she is also the only Seal who is shorter than Kamui, which happens to be one of the first things she notices when she meets Kamui for the first time.
There is nothing fake or pretentious about Yuzuriha—she is enthusiastic, kind hearted, and personable. This makes her an interesting contrast with Kamui, especially at the beginning of the series, who acts withdrawn, callous, and generally hostile. Her and her spirit dog, Inuki, appear for the first time during a particularly tense episode in which Kamui is prepared to attack Hinoto and the others. Her sudden appearance, as well as her casual, somewhat silly demeanor defuses the situation. Even though Kamui eventually lets go of his general hostility towards the others, he struggles with expressing his feelings about them. Yuzuriha, on the other hand, is very open with her feelings, even to the extent of admitting her love for a man several years her senior, who also happens to be a Dragon of Earth.
Still, they have certain commonality, which is the loneliness of their childhoods. While Yuzuriha was never without a friend because of her spirit dog, the reality was that the other kids around her could not see him and thought she was lying. This accusation hurt the incredibly honest young girl, so when she was told that she would one day meet other people who would be able to see Inuki, she was pleased. Having people not trust her word or not being able to share that part of herself made her rather lonely. Kamui, likewise, had very few friends and those that he did, Fuuma and Kotori, had to be kept at a distance for their own safety.
She wants to protect the others on her team, even to the point of making both Subaru and Kamui promise her that they will call on her if they ever need help. It’s in this way that she finally manages to win over Kamui, and her arrival marks a decline in Kamui’s open hostility. Like many of the others, Yuzuriha sees her role in the End of the World as a chance to escape her loneliness, which influences her relationship with Kamui, but really, she likes him for who he is. She sees him as a kind hearted person and she empathizes with his situation, even if she doesn’t understand it fully. Although Kamui never says it directly, he appears to care about Yuzuriha, and worries about her when she disappears after losing Inuki. In a way, the two are like brother and sister, with Yuzuriha as the younger sister who both looks up to and inspires her older, more repressed brother.
For Karen, Kamui represents a sense of purpose in her life--he is someone for whom she can give up her life. She sees her life as fundamentally less valuable than his, especially since he is so young, and has, at times, tried to fight on her own so that the others did not have to put their lives on the line. Seiichirou berates her for this and encourages her to see the true value of her life. She sympathizes with Kamui and encourages him to follow his heart even if it will make other people unhappy. As for Kamui, he has very little interaction with her, but he does seem to care about her in general, as he cares about the other members of his team.
Kamui rarely interacts with Karen, until the day of the final battle in which they, and two companions, go to fight against Dark Kamui, formerly known as Fuuma. Still, before his return to Tokyo, Karen watched the burned remains of his childhood home, wondering what he would be like when they would meet. Kamui is a part of Karen’s destiny and a part of the greater purpose in her life, so she feels a certain kinship with him. Her tender heart also responds to the sadness that surrounds him, so she acts very motherly towards him, gently caressing his face in times of sorrow and telling him everything will be OK. She was once a lonely child as well, so she gives Kamui the affection she was denied when she was very young. Karen ultimately wants to protect humanity, but she also wants Kamui to realize his true wish. She knows that he will only be able to win the battle if he finds out what his heart truly desires.
Kamui has little time to spare worrying about Karen, but he certainly cares about her and considers her a dear comrade. He feels bad for Karen after Kazuki's death, most likely because she was important to Karen and he wants to console her during her time of sorrow. Now that they are facing the final battle, Kamui will have to rely on Karen’s courage and strength to help him as he tries to come to terms with his heart’s true wish.
Seiichirou also appears to be somewhere in this thirties--certainly old enough to have a fairly successful career as a copy editor. He fights as a Dragon of Heaven for the purpose of protecting his family--his wife and young daughter--who mean the world to him. Seiichirou is kind-hearted, soft-spoken, chivalrous (without being condescending), and perhaps a little silly. He seems to care about Kamui in a general sense, but he has even less interaction with him than Karen, who actually has one private conversation with him. It is rather hard to say what influence they have on each other, but they do have a certain contrast that is interesting. Seiichirou is a family man and a generally optimistic person, where as Kamui never knew his father and his experiences have made him rather downcast in his outlook. Seiichirou represents another possibility--the potential for a stable family and a generally happy life filled with common tasks rather than massive responsibilities. Or perhaps his role in the story suggests that family and common life are responsibilities as well that have their own intrinsic value.