NierKai

"I swore I would be a sword! I swore that I would be your sword! So I am going to get you back, and I don't care what it takes!"

- Kaine to Nier.

NierKai is the het ship between Nier and Kainé from the NieR fandom.

Canon
Nier and Kaine are friends and allies who worked together to save Nier’s sister, Yonah. They generally get on well, although their personalities are on the opposite spectrum, whilst Nier is kind, polite and sincere, Kaine is prone to sharp profanity, blunt comments and is generally distant. They nonetheless grow close and appear to develop a romantic interest in each other by the end of their journey.

The two first met when Nier went to visit the Ayrie and came across a scantily cladded Kaine when he stopped outside her house. She immediately attacks him and the two engage in a brief battle before they’re interrupted by a shade, Hook, that had killed Kaine’s grandmother. They manage to drive the beast away but Kaine refused to engage with Nier and they went their separate ways. They reunited again to finally defeat Hook and, following their success, Kaine agreed to help Nier in his quest to save his sister after she was convinced to carry on living.

Their relationship is mostly that of allies as they both fight alongside each other to kill shades. There is scarcely any room for them to directly bond, but it seems Kaine has come to enjoy Nier’s company and will protect him whenever she can. Due to the severe abuse and hardship she experienced, Nier was the first person other than her grandmother who unconditionally accepted her. Although never outwardly admitting it, she came to treasure him deeply to such a point that she went to great lengths to restore his existence so she could be with him again.

Nier also values Kaine greatly and does not at all care that she is possessed by a shade, despite his blood lust to kill them all. Once he has found his sister, he fully intends to work with her and Emil to free her from her shade. Whenever it appeared she had been badly hurt Nier always rushed to her side, and held her gently as she recovered from being taken over by her shade for the first time. He also knows about the deep relationship she had with her grandmother, and how she would make Kaine some lunar tears to put in her hair. As a result, shortly after she is freed from her petrification, Nier gifts her a lunar tear, which appeared to move Kaine. Such is his care for her, he contemplated heading to the Shadow Lord’s palace alone in order to not risk her life, but she overheard him and was furious at the suggestion. He was left with complete rage when Devola and Papola made the decision to not let Kaine, alongside Emil, into the village because the citizens were scared of her.

Throughout her life, Kaine had been emotionally and mentally abused for being different, both for wanting to be a woman, and for being afflicted with a shade, who also tormented her internally. However, Nier appeared to be someone that gave her something invaluable, a friend. Whilst speaking to Tyrant, the shade inside her, Kaine told him she continues to want to live because “he” accepts her, seemingly referring to Nier, which left Tyrant flabbergasted that she was fighting for him. She also considers herself Nier’s “sword” and will fight for him in his quest to save his sister.

Romance between the two is never outwardly shown, but when Kaine was freed from her petrification after five years, she was seemingly flustered at meeting a now adult Nier, commenting at how much he has grown. When Nier first met Kaine, he commented how pretty she is but was slightly thrown off by her personality. Nonetheless, it is clear he came to love her as when he chose to end her life he did so whilst giving her a kiss. Kaine has often acted as a source of reassurance for Nier to get him to act when he starts to despair at their situation, however this is normally done by chastising or slapping him. Nonetheless, this comes from a genuine desire to help him and she appeared saddened when she saw how upset he was when Emil gave his life for them.

Ending C
Their journey together concludes once they defeated the Shadow Lord. Kaine is overtaken by the shade inside her and Nier is forced to fight her. When he defeats her, he chooses to kill her and gives Kaine a brief kiss before she fades away. Tyrant is able to inform Nier that Kaine had suffered greatly in her life but she was eternally grateful for him, both for his friendship and for ending her suffering at long last. He finds the lunar tear that he had given to Kaine and picks it up, remarking that they will always be together.

Ending D & E
Their journey together concludes once they defeated the Shadow Lord. Kaine is overtaken by the shade inside her and Nier is forced to fight her. When he defeats her, he chooses to erase his own existence in order to save her life, knowing that she will forget he ever existed. When she awakens, she is left alone with Nier’s sister, Yonah, and finds the lunar tear that was given to her by Nier. When she picks it up she has a brief flashback of Nier and begins to cry, remarking she has found something special.

Kaine was left with an emotional void following this. She was plagued with a dream of when she first met Nier, but not understanding what or who he was, feeling lost and her mind left foggy over this person she cherished. Later, she was able to enter the memory tree and she gradually began to realise she had lost the memories of someone she held dear. She battled through many enemies and was given help by Emil and Grimoire Weiss to, not only collect her beloved memories of Nier, but to restore his existence. She admonished him for daring to leave her in the first place and further chastised him for trying to convince her to forget him. Eventually, Kaine was able to successfully bring him back as they both emerged from a giant lunar tear, with Kaine holding onto Nier tightly. It is assumed the two spent the rest of their lives together.

Quotes
"Kainé, let's go home. We'll always be together."

- Nier after he finds Kaine's lunar tear.

"You're not the only voice in my life anymore. I'm a curse. A freak... but he still accepts me. He still forgives me... I'll become his sword one last time!"

- Kaine's defiant words to Tyrant as they battle the Shadow Lord

"We made it this far because you were with us, Kainé! I'm who I am today because of you! I'm not going to give up on you! I'm not going to abandon someone I love! I'm going to save you. I swear it!"

- Nier's words to Kaine after she succumbs to her shade.

"These swords of mine need a real home... but you'll do for now."

- Kaine to Nier after she agrees to become his companion.

Fanon
NierKai is one of the most popular ships in the NieR fandom, arguably only rivaled by 2B/9S from NieR Automata. Some fans were surprised when Nier kissed Kainé before killing her in ending C, due to the fact that their romance was downplayed during the earlier parts of the game. However, the downplaying of their romance was done intentionally by the writers for Replicant, who stated that they did not want to muddle the central focus of the game — the relationship between Nier and his younger sister. Despite this, many fans did pick up on hints throughout the game that Kainé had developed feelngs for Nier after the timeskip, and it was confirmed by Yoko Taro (the director of the game) that Kainé had fallen in love with Nier by the end.

NierKai is occassionally rivalled by the ship Nier/Emil. Some even prefer to ship Nier with Grimoire Weiss, especially those who played NieR Gestalt and feel that the age gap between Father Nier and Kainé is too large for romance to be viable. However, NierKai appears to be the most popular pairing in the fandom for Brother Nier, as well as for Kainé.

Fandom
FAN FICTION

FAN ART

Trivia

 * In Grimoire Nier, Yoko Taro stated that the choice between endings C and D was intended to be made based on the player's feelings towards Kainé, rather than Nier's feelings towards her. This implies that Nier's love for Kainé is contingent upon the player's choice. Yoko stated that he gave the players this choice because he didn't want to "shove romance down their throats."
 * However, both endings C and D are romantic in nature. While Nier kisses Kainé in ending C, Yoko had stated that the player would pick ending D if they came to like Kainé after playing through the game twice. Because both final endings seem to imply that Nier harbored feelings for Kainé, many fans view the love between the two characters as mutual and requited.
 * The main storywriter for Replicant, Sawako Natori, stated that he had wanted to explore the romance between Nier and Kainé in a few more places while writing the scenario. However, Yoko had asked him to change these scenes, stating that they would take away from the main focus of the plot, which was Yonah's rescue.
 * In Jun Eishima's (writer of the light novels) interpretation, ending C is Father Nier's choice while ending D is Brother Nier's choice. Natori expanded on this, stating that, if Emil were the one to die rather than Kainé, then Brother Nier would still sacrifice himself to save Emil. This implies that, at least in Natori's interpretation, Nier's sacrifice in ending D is not necessarily romantic.
 * Yoko stated that the moment where Kainé beats Nier up in the Shadowlord's castle is the moment she realizes she loves him, and that it is the most romantic scene in the game.