Yuki & Kaname

Yuki Cross and Kaname Kuran have a long history and have a complex, if somewhat at times, mysterious relationship.

Background
Kaname once declared that Yuki was born to be his wife. As a child, Yuki adored her older brother and the two shared a close relationship. Due to fears over her safety, Yuki's birth was kept secret from the rest of vampire society, and for the first five years of her life, she was kept hidden from the outside world, locked in the basement of the Kuran manor with only her parents and older brother as companions.

Yuki's parents managed to keep their daughter safe until the night Rido Kuran attacked the Kuran household, killing Haruka in the process, and spurring Juri into sacrificing her own life in a final attempt to protect Yuki by transforming her into a human. After severely injuring Rido (but unable to land the killing blow), Kaname took the unconscious Yuki to the home of Kaien Cross, a former vampire hunter and longtime friend of the Kurans. Upon awakening, Yuki no longer remembered the first five years of her life, instead believing that she had been saved from an angry vampire in a snowy field by Kaname, giving Kaname the lasting impression of a savior in Yuki's thoughts.

Yuki then spends the next 10 years of her life living as Kaien's adopted daughter while Kaname is taken in by the Ichijo family under the watchful eyes of the vampire council.

During this 10 year separation, Kaname is frequently tricked by Kaien into visiting Yuki, opportunities which allow the two to grow close once again, and which gives Kaname a temporary respite from the vampire council. With Yuki, Kaname is able to laugh and relax and behave more like a normal teenager as he fondly watches over her. Kaname also makes it a point to visit Yuki each year on the anniversary of her being saved from the angry vampire, a day Yuki calls her birthday. The human Yuki grows trusting and fond of Kaname and holds a strong belief in his kindness based upon his gentle caring of her. She soon falls in love with Kaname and begins looking forward to each of his visits.

Despite their closeness in her early childhood years, Yuki and Kaname's relationship changes after the creation of Cross Academy. Knowing Kaname is living nearby in the school's dormitories, Yuki decides to pay him a visit. Unable to locate him, she falls asleep on the dormitory stairs while waiting for him. Kaname finds her soon afterward nearly gives into the temptation of drinking her blood, stopped only at the last minute by Ruka. Kaname then takes Yuki to his bedroom and proceeds to drink Ruka's blood in an attempt to quell his hunger. Yuki awakens while Kaname is still drinking Ruka's blood, the scene causing her to run off in shock and fear. Finally having come to understand that vampires and humans truly are different from one another, Yuki's relationship with Kaname becomes more distant than it once had been, to the sadness of both.

Prior to Yuki's Awakening
At the beginning of the series, Yuki is 15 years-old and a first-year student in the Day Class at Cross Academy, where she also acts as a school Prefect/Guardian. As the Night Class president, Kaname is one of the most popular and influential students at Cross Academy, and seemingly unreachable for a normal girl like Yuki. However, the Night Class share a secret which only the school Prefects, Yuki and Zero Kiryu know: they are all vampires, and Yuki and Kaname also share a secret past of their own: Kaname once saved Yuki from a vampire when she was 5 years-old. Thanks to this, Yuki regards Kaname as her savior and the two enjoy a special bond. Kaname calls Yuki his "dear girl" and Yuki quietly returns his affections, though often feels awkward and inferior around Kaname due to his status as a respected Pureblood vampire.

Although Yuki states that she is in love with Kaname, she finds his attachment and his gentleness toward her inexplicable as Kaname spends much of the first arc working to protect Yuki, which includes killing Shizuka Hio and fostering Zero's powers.

Yuki's awakening
As Rido Kuran closes in on Yuki at the end of the second arc, Kaname bites her, reawakening Yuki's vampire side and returning the lost memories of the first five years of her life. Yuki is initially disturbed upon her awakening at the thought of being in love with her brother, but Kaname reminds her that they are engaged and that intermarrying is a common practice among Purebloods as their mother and father were also siblings.

Kaname then suggests he and Yuki leave the school in order to escape from Rido, a plan Yuki refuses out of a sense of duty as a school prefect and a need to protect her friends, and on the basis that wouldn't forgive herself if she ran away. Kaname is upset at her refusal; however, Yuki kisses him and promises to return to him afterward. Yuki keeps to her word, and after the fight with Rido ends, she parts with Zero and returns with Kaname to their family home. There Kaname finally confesses all that he has done to protect her, including using Zero's bond with Yuki. Yuki is initially upset, but accepts his sins and wishes to share the responsibility for actions done on her behalf.

During the fight with Rido, Kaname destroys the corrupt vampire council, an act which sends vampire society into disarray and earns him a number of enemies. Kaname spends the year following Rido's attack reorganizing vampire society and maintaining the peace. Afraid for Yuki's safety, Kaname has her remain inside the Kuran mansion during this time and limits her contact with the outside world requesting that Yuki neither communicate nor have visitors at the manor.

Also during this time, Yuki returns to calling Kaname "brother (formally)" and occasionally "Senior Kaname" despite his repeated requests to simply call him "Kaname." In addition, she experiences some difficulties relearning how to use her fangs and seems to be in a perpetual state of bloodlust and hunger, desperate for Kaname's blood. Although Kaname regularly gives her his blood, Yuki reveals that without Zero's blood, Kaname cannot satisfy her hunger; and in spite of this she asks to remain by his side despite this. Kaname accepts her request and returns Artemis to her stating that he would rather be killed by her than being apart.

Following the return of Artemis, Yuki leaves the house and gets into trouble after being attacked by another pureblood vampire, Toma, whom Kaname severely punishes for hurting Yuki. Kaname then reveals that he fears losing her deeply as this has happened to him before.

Kaname the ancestor
After finally telling Yuki that he is not her real brother, Yuki drinks Kaname's blood and is swept up in his memories, witnessing Kaname's reawakening by Rido, which included the murder of her true brother, and Kaname's distant past as the ancestor who saw the rise of vampires. As one of the ancestors, Kaname fought to ensure humanity's survival, following the Hooded Woman, another vampire who organized the pureblood vampires, protected the humans, and later created the Vampire Hunters. As his friend, mentor, and possibly lover, the Hooded Woman's death left a deep impression upon Kaname, prompting Yuki to ask Kaname if the Hooded Woman could ever be replaced. However, Kaname assures her that no one is ever a replacement for another. Years after the deaths of all his companions, Kaname eventually lies down in his coffin, intending to sleep forever now that he had been left as the last of the ancestors.

After awakening from Kaname's memories, the two discuss what she has seen. When Kaname asks Yuki what she thinks of him, she responds that she knew him as her brother, her senpai, and now he is her ancestor. Yuki declares that she will call Kaname by his name from then on, rather than "brother (formally)" as she had been. She also states that Kaname is a beast like her, is a bit weak, lies, is dodgy, and has too many secrets. She is also a bit uncertain of his feelings for her, but amends that he loves her, however there are other things mixed up in his feelings for her. Ultimately her best answer to his question is to ask if they can start over and she can watch him properly, to which he hugs her tight and agrees.

Separation
After saying goodbye to Yuki, Kaname leaves saying that he has very important duties to attend to, leaving Yuki alone in the mansion with Hanabusa's father. Prior to his departure, Nagamichi Aido asks Yuki if she would be able to stop Kaname if she thought he was doing something she disagreed with. Yuki states that she can't do anything if she is still not Kaname's equal. Afterward, still confused by Kaname's last remark to her and beginning to feel a sense of unease, Yuki runs out of the mansion hoping to find Kaname. Instead, she runs into Kaien and Hanabusa, and together, the three find Kaname with Hanabusa's father. To everyone's shock, Kaname slays Hanabusa's father. Kaname turns to Yuki and advises her that he can no longer hesitate and is returning to his original plan. He apologises and thanks Yuki before disappearing. After Yuki unfreezes from her shock, she chases after Kaname as well, in a desperate almost crazed state. She accidentally attacks Kaien who tries to calm her down and eventually arrests her.

Yuki gets taken to the Vampire Hunter's headquarters for further questions, but Yuki is unable to answer any of Kaien's questions as Yuki doesn't know what Kaname's intentions are. Yuki vows to keep the peace between vampires and humans, and demands that she be the one to confront Kaname. Yuki spends the next few weeks re-establishing the night class and delays going after Kaname. After Yuki hears about Kaname killing more purebloods, she refuses to believe it and mentally begs for Kaname to stop. When the hunters declares they have no intention of stopping Kaname, Yuki tells Zero that she wants to stop Kaname.

Kaien presses Kaname for answers to what he is doing and Kaname declares that he ought to understand and refuses to deny that he is killing all the purebloods. Kaien fears that Kaname may even include Yuki.

Their Relationship
Due to Yuki's widely changing circumstances, the nature of Yuki and Kaname's relationship has gone through many changes.

Yuki as a human
Often uncertain of Kaname's feelings for her, Yuki claims he sees her as nothing more than a pet, despite the fact that Kaname often refers to her as "his dear girl." During their separation, Kaname often appears lonely, and Yuki observes that besides herself, few people are close to him.

As a child, Yuki always referred to Kaname as her "Onii-sama" (a respectful and formal Japanese term for elder brother), while after turning human, Yuki at first called him "Kaname" (informal), but after their relationship became distant she began referring to him as "Kaname-sama" (respectful and formal), and "Kaname-senpai" (respectful address for an older student) while at school. Yuki revealed in 25th Night that she had been determined not to refer to Kaname as "Kaname-sama" in a deliberate attempt to distance herself from Kaname, but still accidentally finds herself using it.

After Yuki's Awakening
Following her reawakening, Yuki returns to calling Kaname "Onii-sama" and occasionally "Kaname-senpai," despite his repeated requests to simply call him "Kaname." During this time, Yuki and Kaname appear to be affectionate with one another and share occasional kisses; however, it's later revealed that Yuki continues to feel inferior to Kaname, making her unable to address him informally and preventing their relationship from progressing forward.

In spite of her feelings of inequality, when asked by Kaname how she sees him after revealing his past to her, Yuki responds that she thinks he keeps too many secrets, is a liar, and is somewhat vicious. Yuki suggests that the two start over again, so that she can get to know the real Kaname. Unfortunately, this does not lead to many answers as Kaname leaves Yuki shortly after this, determined to carry out the plan he had formed years earlier before his revival. Kaname's own feelings on the status of his relationship with Yuki are extremely ambiguous, but prior to enacting his plan, he had indicated he still wished to return to Yuki and as indicated to Kaien, his primary reason to separate from Yuki is due to her being a hindrance to his plan.

The conclusion can be drawn that Kaname's deems his plan to be more important than his relationship with Yuki, though it is speculated that he could be doing this for Yuki, in spite of the fact that she may not approve.