Nier Replicant: The Philosophy of Egoism, the Origins of Self-Awareness in Love, All Veiled in Revealing Outfits

Nier Replicant was originally released in 2010 and received an updated version nearly a decade later, titled NieR Replicant ver.1.224744871, which I recently completed. And for me, Nier Replicant became yet another piece of evidence that video games are a true form of great art. Behind the revealing anime-style outfits and the PS3-era gameplay lies a story filled with complex themes — from the moral right to kill, to the question of what truly drives people. This isn’t a breakdown of the plot or the game’s philosophy, but rather my personal impression and understanding of NieR Replicant

Disclaimer: This article contains spoilers for NieR Replicant ver.1.22474487139…, including all possible endings, as well as for the novella Grimoire Nier.

From Love to Hatred

At first glance, it seems like a fairly typical Japanese RPG. You play as Nier (that’s his “canonical” name — the player can choose a different one, but for the sake of clarity and the related novella, I’ll stick with Nier), a rather standard protagonist who’s trying to save his sister Yonah from a mysterious illness. Everyone around them is aware of the young girl’s condition and helps by hiring Nier for various odd jobs and errands. Their parents are gone, and Nier is doing everything he can to take care of his sister on his own.

But it’s incredibly difficult. Nier Replicant takes place in a post-apocalyptic world where humanity has been nearly wiped out by a deadly pandemic and continues to decline.

It’s a grim place, full of dangers. Aside from wild animals, the main threat comes from deadly Shades — black, shadowy creatures that roam in the dark and fear the sun. From the very beginning, players are given only a minimal understanding of the world and its rules. To truly grasp what’s going on, you have to play through the game — not just once, but several times.

When you play the game, you might find yourself asking: “Why is the world in ruins? Why are monsters attacking people?” But we did that intentionally. When we look at the real world, we often see that, even though the reasons aren’t entirely clear, these things still exist. For example, I understand that religious conflicts still happen in different countries and regions, but even if I dig into the long history of why they began, I still won’t be able to fully grasp the details — especially the emotional aspects. So, I wanted to leave some parts of the game intentionally vague. I also wanted to show how senseless things can happen — just like they often do in real life.

Yoko Taro (横尾 太郎) Director and Writer of NieR

Nier and Yonah are orphaned children, left to survive on their own — and that’s no easy task. Here, you can clearly see the protagonist’s overwhelming sense of responsibility toward his sister. He’s willing to do absolutely anything for her.

Yonah

In the story Red and Black (a reference to my favorite Stendhal) from the Grimoire NieR collection, we learn that Nier was forced to sell himself to a man in exchange for money, which he needed to care for his sick sister, Yonah.

Since Nier started visiting this man more frequently, he grew to hate his own hair. He felt disgusted even when it touched his shoulders. Every time, it made him remember how the man would roughly grab his hair, and what he had to endure afterward. He tried to forget, but the experience had burrowed too deep inside him, constantly resurfacing and tormenting the already tortured Nier.

Excerpt from Grimoire NieR

Over time, Nier decides to earn money by hunting monsters. One day, he sets out with a team of three hunters to destroy a group of Shades. One of these Shades turns out to be the very man. During the battle, they’re enveloped by a thick fog, and as they slay one Shade after another, Nier tastes blood and begins to see himself and the hunters as the bloodthirsty monsters, while the Shades seem more human than the people around him. Nearby, he notices the man who caused him so much pain.

In the next paragraph, the battle is won, and the man, according to Nier, dies at the hands of a monster.

Nier looked at his bloodstained hands. His palms were dry, dark red — a color that no longer allowed him to distinguish whether it was human or Shade blood. The man from the seaside was dead. Nier would never have to return to that house again.

— “Are you okay? Does something hurt?”

The concerned voice brought Nier back to his senses. He looked away from his hands and shook his head.

— “I’m just thinking we should get back home quickly.”

The image of Yonah waiting by the second-floor window appeared in his mind. Probably, as always, she would greet him with a warm smile. There was no point in thinking about anything else. Only Yonah mattered. Nothing else was important…

Excerpt from Grimoire NieR

Yonah becomes not just the object of care, but the very meaning of life for the protagonist. Throughout the game, we witness incredibly touching and emotional moments between Yonah and Nier. It’s not just dialogue or side quests, but also letters from her and even sweet loading screens.

If we strip away the details, the story begins when Yonah learns about a magical flower that can cure her illness and sets out to find it.

The game essentially divides into two parts. In the beginning, Nier is a boy who, with childlike ease, explores the world around him and makes friends during his search for a cure. These characters become incredibly important to both you and Nier personally.

Almost like family, Devola and Popola are always there to help the brother and sister. The great and wise Grimoire Weiss will be your loyal companion and assistant, though he tends to grumble a bit throughout the game. The incredibly sweet, albeit rough, warrior Kaine is always ready to come to your aid. The boy Emil, with an incredibly kind heart. And then there’s the Masked Man and the talkative postman, who loves his wife and apples. They are all not just anchors for immersion into this beautiful world; through them, Nier begins to develop deep feelings for those around him. Yonah remains undeniably the most important, but other beloved characters start to emerge as well.

The second part of the game is much darker. Childhood ends with the kidnapping of his closest person, his sister, and the loss of his best friend for many years. The world cracks before Nier’s eyes. He lacked the strength to protect the people most important to him. And it’s all the fault of the Lord of the Shades.

A choice without options.

Am I a trembling creature, or do I have the right?

Five years later, our protagonist continues his futile search for Yonah. Nier himself transforms from a charming teenager into a strong young man with a worn and grim face. After years of battles, the adult Nier, killing more and more silent Shades, becomes consumed with hatred for them. There are no longer any thoughts of understanding or compassion within him. Throughout the entire post-time skip plot, each of his loved ones undergoes horrific suffering, and even death. But he has one goal: to save his sister, and it doesn’t matter what he has to do to achieve that.

At the end of the first playthrough and in subsequent ones, my favorite narrative device occurs — the “Reversal.” This is when the perspective shifts for the same situation, much like in the films Shutter Island, The Favourite, or The Last of Us Part II.

NieR Replicant does everything possible to show us how actions that seem right to US are monstrous to others. The game makes us feel guilty when we realize the full picture of what’s happening. After all, ignorance does not absolve us of responsibility.

The main plot twist is that almost all humans are replicants — vessels designed to be filled with human souls that became the Shades.

He swung his sword as if in a trance, over and over, bathing in the spilled blood. No matter how many Shades he killed, new ones appeared from the mist, and their silhouettes began to strangely resemble humans: heads, limbs, similar movements… After a while, Nier could no longer tell exactly who he was killing. Perhaps from the very beginning, these weren’t Shades, but humans? Perhaps this sticky red blood — was it human?

Excerpt from Grimoire NieR

The separation of body and soul was necessary to save humanity from the epidemic. But there was a mistake in the project, and the replicants gained their own consciousness.

During subsequent playthroughs, we are shown another side of the story — from the perspective of the Shades. With his own hands, Nier is killing humanity, and most importantly, he must kill himself. For Nier is the Lord of the Shades, and the protagonist is a replicant who has gained self-awareness.

Yoko Taro, the director, has always been fascinated by the question of why and for what reason people kill. In an interview, Taro shared how, when creating Drakengard, he thought that only madmen commit murder.

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In NieR Replicant, he ponders what force drives people to kill.

During the Iraq War, when the media reported on terrorist organizations and the violence unfolding in the Middle East, Yoko Taro thought:

“You don’t have to be crazy to kill someone. You just have to think that you’re right.”

— Yoko Taro

Here, I believe Yoko Taro is exploring several themes: Descartes’ philosophy of consciousness, the connection between motivation and egoism, with a touch of Dostoevsky’s existential struggle. The idea that people, when convinced of their own righteousness, can justify even the most heinous actions resonates with the human tendency to rationalize violence through personal belief systems, mirroring Dostoevsky’s exploration of moral conflict and self-delusion.

“Cogito, ergo sum” (“I think, therefore I am”) is a famous statement by the French philosopher René Descartes. He believed that the foundation of the world depends solely on one’s own existence. It’s not the physical body that matters, but only the mind.

Thus, a person cannot doubt their own existence, because the very act of thinking is proof of it.

A prime example of this in NieR Replicant are the twin androids, Popola and Devola. They are unique in that they know the truth about their artificiality and accept their purpose. However, after their defeat, as Devola is dying, she reflects on how soulless machines can cry. She tries to rationally deny that she is alive, but it’s precisely her attempt to do so that makes her “human.”

In this way, Yoko Taro explores the nature of consciousness and existence, drawing on Descartes’ philosophy to suggest that even beings designed with no soul can achieve a form of humanity through their emotional experiences and self-awareness.

Consciousness is what allows motivation to arise, and this forms the basis of the central conflict between Nier and the Lord of the Shades. Our protagonist thinks about himself, his sister, and those he holds dear, which means he is not just a vessel for a soul but a human being. A human being who has every right to a happy life. And the Shades also think, and therefore have desires. The Lord of the Shades sees Nier as nothing more than a puppet, or more precisely, his own body. Two beings that are essentially identical but differ in appearance clash in a deadly struggle, each convinced of their own righteousness.

This conflict highlights the theme of identity, self-awareness, and the right to existence, where both sides are locked in a struggle to assert their belief in what it means to be truly alive. Both Nier and the Lord of the Shades, despite their differences, are driven by their own understanding of what is just and what is right — and in that, they both embody the struggle for meaning and purpose.

How much selfishness is within us

Nier’s confidence in his own righteousness allows him to kill the Shades and not only them without a second thought. In his quest to save Yonah, even if accidentally, he destroys an entire settlement of Shades and replicants. He doesn’t engage in self-reflection, instead pressing forward, because there’s no time for self-examination.

This unwavering sense of purpose, driven by the desire to protect those he loves, blinds him to the moral consequences of his actions. His belief in the righteousness of his cause gives him the strength to keep going, but it also highlights the dangerous power of unchecked ego and self-justification.

I believe it’s selfishness that drives nearly all the characters. Let me try to explain. Selfishness is often understood as self-love, where a person is primarily focused on satisfying their own interests.

Kaine always knew, thanks to the entity within her named Tyrann, that the Shades were once real people. She could hear their cries of despair and pain. One of the most heart-wrenching scenes in the game, probably one of the final battles in the second playthrough, is when Nier kills the black round Shades that attack randomly. Kaine understands their speech and realizes that these enemies are actually babies, and that their attacks are unintentional. Yet, even knowing this, they continue to commit infanticide. She keeps this information hidden in order to keep fighting alongside her loved one and to exact revenge for the death of a close person.

This illustrates how selfishness manifests not only as a drive for survival but also as a refusal to confront the truth in order to preserve personal motivations, whether it’s love, revenge, or the need for justification.

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And Grimoire Weiss decides to help Nier save Yonah even after his memories are restored. His original purpose was to return the Shades to their replicant bodies, but he chooses to abandon his duty. Selfishly, he condemns humanity to death for the sake of his friend’s happiness.

This is true for almost every character. They prioritize the personal over the collective good. From the single mother who wanted to start a new life without her children, to the monstrous Shade that devours people in order to become an ordinary girl and live with the beloved postman. But Yoko Taro doesn’t condemn them; instead, he attempts to show how unjust the world is. Their desires are simple and understandable, yet often, due to obstacles, people end up sacrificing something or even someone. In these stories, there are no true heroes or villains.

Altruism, the opposite of selfishness, was a concept first proposed by the French philosopher Auguste Comte in the 19th century. He believed that altruism was the embodiment of the “live for others” principle, which could transform human society toward greater humanization. Essentially, it’s a variation of the Christian teaching “Love thy neighbor as thyself.”

In NieR Replicant, it is often altruism that offers a way out of the cycle of pain and hatred in the world.

The final battle between Nier Replicant and Nier, the Lord of the Shades, represents the peak of both characters’ desires. Just like Nier, the Lord of the Shades allowed personal feelings to outweigh the greater good, prioritizing his own desire to reunite with the original Yonah. His love for her, like Nier’s, was his only and most powerful motivation. For over a thousand years, he had longed for this, enduring pain and suffering along the way.

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But it is Yonah’s act that ultimately ends their selfish battle. The replicant body of Yonah is taken over by her original self, but she can still feel the consciousness of her replica inside her. Yonah decides to relinquish control of the body and allow the consciousness of the Replicant Yonah to take over once again. This is an act of pure altruism and self-sacrifice.

Inside this body, there’s another girl. I hear her. She continues to cry. She says she wants to see her brother. This girl also loves her brother, just like I do. She loves him just as much.

— Original Yonah

It’s crucial to understand that Yonah loves her brother dearly, as seen from the very first cutscene of the game. For her, there is no one more important. Yet, despite this deep love, she refuses to build her own happiness on someone else’s tragedy, even knowing that this action will cause the death of the original Nier.

Yonah’s sacrifice is an ultimate act of love and selflessness. In choosing to let go of her own desires for the greater good, she breaks the cycle of egoism that has consumed the characters throughout the game.

And here we arrive at the bittersweet ending. Our Nier has defeated the Lord of the Shades, saved Yonah. However, the malicious Shade living inside Kainé, named Tyrann, unknowingly takes control of her, and Nier is faced with an impossible choice. He can either kill Kainé, as she asks, or save her, sacrificing his own life and even his memories of himself.

Throughout the game, Nier never questions his goal: for him, saving his sister is everything, just as it was for his original.

“Do you want me to understand your sadness? Do you think I will sympathize with you? I swore to protect my sister and my friends. If anyone threatens them, they must step aside or be killed! I have something to protect! I have a reason to live!”

— Nier Replicant

In order to achieve the “true ending,” Nier sacrifices himself, much like in the biblical story of Jesus Christ with his version of Saint Dismas — the Tyrant. Even more selfless, as he literally erases himself from existence. No one will remember his heroism, no one will mourn him. Despite his desire to be with his sister, he chooses to abandon his own happiness for Kainé’s sake.

To love is to live with the heart

I believe that egoism and altruism are impossible without the feeling of love! It’s a paradox because what drives people to commit the worst acts also gives us the strength for incredible deeds.

This is clearly seen in the stories of Emil and Kaine.

Probably the brightest character in the entire game is Emil. His story from start to finish is a journey of altruism. A young, sensitive, and very kind boy, living in a gloomy mansion with only his butler. For hundreds of years, trapped in the body of a little boy, he is cursed with loneliness. Anyone who meets his gaze turns to stone. He is like Medusa from Greek mythology. But Nier and Kaine are not afraid of him; they see not a monster, but a friend.

Unfortunately, the irony only deepens his suffering in the second half of the game. During his search, he recalls that long ago, a research group used Emil and his sister as weapons. He absorbs his unfortunate sister Halua to regain control over his eyes, but this comes at a great cost — his body turns into a skeleton with a smiling skull. Emil shrinks after his transformation, fearing that he now finally looks the way he has always felt: alien to the world and unattractive. He is no longer afraid of being see; he is afraid of being seen.

Emil is Emil

But for Nier and Kaine, none of that matters. They love him no matter what, because Emil is Emil. Even though humanity turned him into a weapon of mass destruction, thanks to the incredible support from those who have become his true family, he learns to cherish his existence.

And by the end of the game, Emil, who desperately wants to live, sacrifices himself to allow Nier and Kaine to survive. Emil’s love for his new family is a love that will last for millennia.

You know… when I was young, I… I hated my eyes. And now, as I’m older, I hate what my body has become. But now there’s something else. Something like… pride. Do you understand? I mean, without all of this… I wouldn’t have been able to become your friend.

Emil

But on the verge of death, Emil is visited by his sister Halua. Through her, he remembers all the love and kindness that filled his life, and this gives him the strength to survive. There’s also a very funny story about Emil called Around the World in 80 Days from the same novel. He literally starts rebuilding himself from scratch (well, from his head), because his friends need him!

How will I rebuild my body if this keeps going on? Kaine and Weiss will surely kill each other if I don’t hurry. Kaine is so harsh, and Weiss is so annoying.

I need to go! I want to see Nier as soon as possible!

Emil

Kaine’s story is deeply emotional and complex. She was just as lonely as Emil. Raised by her grandmother on the outskirts of the city, Kaine faced extreme discrimination and abuse because she was different. The people in the town bullied her, kicked her, beat her, and threw stones at her.

“Why do you act like a girl, huh? Everyone knows what you really are! Freak!”

Thug

The thing is, Kaine is intersex. In the story, it’s explained as a technical error during the creation of her replicant body. To express her femininity, Kaine dresses in a highly sexualized way. She takes pride in who she feels she is, not in what others tell her she should be.

This trait of Kaine’s body made her an outcast to the people around her, but her grandmother became her most important and only support. Kaine had a role model to look up to, someone who accepted her as she was. All the strength, selflessness, and even her excessive roughness came from her grandmother. Such strong love gave her the power to live and, most importantly, to be happy.

One day, a huge shadow attacked their home, killing her grandmother and mortally wounding Kaine. She lost her arm and eye. She was ready to die, feeling guilty for not saving her grandmother, but then the shadow, Tyrann, offers her another way out: the path of revenge and killing. Thus begins the symbiotic relationship between him and Kaine. He needs her to achieve his goals, while her path of hatred feeds Tyrann’s boundless bloodthirst.

“I am a very powerful being, Sunshine. And now this power belongs to you. Do you have enemies? People you want to kill? I can make that happen! That little fat guy who kept bothering you? That big monster who crushed your grandmother? We’ll shove them up their own asses! No more insults for you, Sunshine! No more pain!”

Tyrann

Tyrann is a unique character in this game. He is a completely bloodthirsty sadist, devoid of any kindness. He is filled with contempt for all living beings.

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This relationship clearly references the Daoist concept of yin and yang: the black — Tyrann, the shadow; and the white — Kaine. Their fusion further complicates Kaine’s life. This is beautifully illustrated in the short story Witch’s Sabbath. In it, the villagers see Kaine as a monster who attacks both shades and humans — even though she is actually their protector. Even a pilgrim, who at first seems friendly and kind, reacts with horror when confronted with Kaine’s intersexuality and possession.

“Her eyes narrowed, and her parted lips formed a thin slit across her face. Her gaze fixed on me like a hunter eyeing prey, and her left hand began to move rapidly up and down. Her breath grew even more ragged, and her upturned eyes started to lose focus. I knew what would happen next.

‘Stop!’ I shouted, turning away before her ecstasy could reach its peak. ‘Don’t come near me, you… monster!’

As I ran away as fast as I could, her piercing voice chased after me like a ghost. It was a shrill scream — a twisted mixture of laughter and sobbing.”

From the perspective of the pilgrim

Her kind intentions are slowly drowned out by fear and prejudice, while Kaine’s inner anger and pain grow stronger. However, Nier’s intervention takes Kaine down a completely different path. Traveling alongside him gradually fills her with love. This becomes undeniably clear during the moment of fulfilled revenge.

After the final battle, Kaine loses the will to live — the only person she truly loved is gone. But Nier reminds her that she still has people who care about her. Throughout the game, Kaine slowly opens up more and more, gradually filling with love. She eventually comes to understand that Tyrann is not a curse, but rather a person lost in hatred — much like she once was. Her compassion and warmth reach even someone like Tyrann.

Tyrann: “Wait… No. No, no, no! That wasn’t fun at all! I turned you into a killing machine! I spread evil and chaos across the world! But now everything feels so empty! Why!? I don’t understand!”

Kaine: “I’m sorry, Sunshine. Maybe… you’re better than you thought you were.”

Tyrann: “Stop! Don’t treat me like this! I hate when people are nice to me!”

By the end of the game, Kaine — through her love for Nier and others — is able to pass those feelings on to Tyrann. In the end, he performs the only good act of his long existence: he sacrifices himself to save Kaine.

And so, the game reaches its end — Yonah is saved, Kaine’s life is spared, and the concept of altruism triumphs.

…Or does it? Kaine disagrees.

The so-called “final” ending is actually a scream of pure egoism. We reject the idea that this bittersweet conclusion should be the only path. Kaine is ready to fight even the “gods” themselves for her happiness — for her choice. Maybe it will lead to catastrophe. Maybe it’s wrong. But she believes it’s worth it.

Yoko Taro blurs the line between egoism and altruism, one flowing into the other and back again. In the end, Kaine regains her memories — and her love.

In human life, both selfish and selfless motivations matter. There is no single right answer — because everyone deserves to be happy.

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And why did I write all this?

Trying to analyze the ideas or make a review of NieR Replicant is a bad idea — trust me on this. Even Yoko Taro himself doesn’t consider his games to be filled with deep philosophy.

“You’re reading too much into everything. Yoko always thinks only about superficial things.” Yoko Taro

Of course, he’s being quite disingenuous here — but there’s some truth to it. We often project something of ourselves into the works of others. The main strength of NieR lies in its ability to touch the player’s soul.

For most of the time, the gameplay is average at best. But it is overflowing with emotion. Speaking at GDC in 2014, Yoko Taro mentioned that gameplay — combat, side quests, and so on — is not the main focus of his games. Instead, it’s the characters and how the story twists make the players feel that truly matter to him.

In his younger days, Yoko Taro naively believed he could bring about social change through the stories he told in games. I personally think Mr. Taro is a great humanist. His games are filled with love and kindness — even if wrapped in tragedy.

And to understand that, you just have to play them. They’re worth it.

“In the past, I couldn’t change the world through games — and I continue to fail even now. But I still believe in the potential that lies within games, and I dream that someone young and new might one day succeed.” Yoko Taro