Earthlings

Yuu Sasamoto functions as a deuteragonist and a crucial figure in Natsuki’s psychological development. As a dynamic and round character, his trajectory involves a departure from and eventual return to the alternative reality he creates with Natsuki. In childhood, Yuu mirrors Natsuki’s feelings of alienation, readily accepting her magical worldview and contributing his own narrative of being an alien abandoned on Earth, waiting for a spaceship to take him home. This shared identity as outsiders solidifies their bond, making him the only person who understands and validates Natsuki’s reality. Their childhood marriage and the pledge to “[s]urvive, whatever it takes” establish a pact that transcends conventional relationships (30), forming the foundation of their enduring connection and shared rebellion against the adult world.

As an adult, however, Yuu represents the struggle between nonconformity and the powerful pull of societal assimilation. When he reunites with Natsuki and Tomoya, he has attempted to shed his alien identity, insisting he is a “fully fledged Earthling” who must survive by obeying the unspoken “orders” of society (131). This period of his life reflects a deep-seated survival instinct that he expresses through pragmatic conformity. Upon meeting Natsuki again as an adult, he is initially repulsed by Natsuki and Tomoya’s Popinpobopian philosophy, viewing it as a childish fantasy that is incompatible with adult life. His internal conflict between his authentic self and the person society demands him to be creates a central tension, positioning him as a foil to Tomoya and Natsuki.

Ultimately, Yuu’s journey is one of rediscovery and liberation from the societal programming he has internalized. Conformity doesn’t bring him peace or the belonging he seeks, and as he resides with Natsuki and Tomoya and talks to them about their worldview, he chooses to abandon his attempt to become an Earthling and commits to living with them in their “alien” community in Akishina. This decision marks his complete character arc, moving from a shared childhood fantasy to a failed attempt to meet society’s expectations, and finally to a conscious adult choice to embrace a radical, alternative existence. He fully commits to the group’s new logic, participating in the murder and cannibalism that signal their final break from humanity. His suggestion that the others should eat him if they run out of food is the ultimate expression of his rejection of Earthling norms, demonstrating that he has found a new way to fulfill his and Natsuki’s childhood pledge of survival.

Tomoya Miyazawa, Natsuki’s husband, is a deuteragonist who serves as the primary ideologue of the trio’s anti-societal community. A dynamic and round character, he evolves from a man seeking a quiet escape from social pressures into the intellectual architect of the Popinpobopian identity. Tomoya’s rejection of society, also rooted in parental abuse, finds expression in a reasoned, philosophical stance. He finds Natsuki through a website for people seeking marriages of convenience, stipulating a partnership with “[a]bsolutely no sexual activity” to escape family surveillance (103). This pragmatic approach to subverting societal expectations makes him a perfect ally for Natsuki. He is the one who gives a name to Natsuki’s feelings, articulating her sense of oppression by calling society “the Factory” and its conventions a form of “brainwashing.”

Tomoya’s entrance into Natsuki’s life acts as a catalyst, validating and expanding upon her worldview. He introduces the concept of the “alien eye,” a perspective that allows one to see the world’s irrational nature, and proudly claims his identity as “Popinpobopian.” He carries their ideas to what he sees as their logical conclusion, and his desire to deprogram himself leads him to propose extreme acts, such as committing incest with his brother, which he frames as a logical experiment to break one of society’s greatest taboos and thus break society’s last hold over him. Tomoya is fully invested in Deconstructing the Logic of Human Norms, as he posits that society’s most sacred rules are no more rational than the acts of those who defy them. He believes that true freedom from the Factory can only be achieved by systematically dismantling its most fundamental norms.

While Natsuki’s rebellion is rooted in personal survival, Tomoya’s is a conscious and intellectual war against societal norms. He calmly asserts that “love is a drug” and an “anesthetic” designed to make the act of procreation tolerable (219). He is instrumental in persuading Yuu to abandon his attempt at conformity and rejoin their cause. Tomoya’s main role in the novel is to develop Natsuki’s notion of the Factory and take it to its furthest conclusion, providing the language and philosophical framework for their final transformation. He reframes their isolation and cannibalism not as monstrous acts but as a rational mode of survival for a different species. It is his intellectual framework that allows the trio to perceive themselves as evolved beings, creating a new world order.

Kise, Natsuki’s older sister, acts as an antagonist and a foil to Natsuki. A static character, she represents the tragic outcome of an individual who, after suffering under societal pressures, becomes one of its most fervent enforcers. In her youth, Kise was a victim of bullying, cruelly nicknamed “Miss Neanderthal” for being hairy (26). Her response to this persecution is not rebellion but a desperate clinging to the very system that harms her. She seeks validation from her mother, which she achieves by bullying and scapegoating her sister, juxtaposing Natsuki’s nonconformity with her own adherence to expectations. This dynamic establishes her as Natsuki’s earliest tormentor, kicking her when she is on the phone and complaining that Natsuki’s very existence causes her stress.

As an adult, Kise fully embodies the values of the Baby Factory. She marries, has a child, and dedicates herself to upholding the societal norms of family and motherhood. She relentlessly pressures Natsuki to fulfill her “duty” to procreate and is openly hostile toward Natsuki and Tomoya’s unconventional, childless marriage. Her role as an agent of conformity culminates in an act of profound betrayal when she provides Mr. Igasaki’s parents with the evidence that Natsuki killed their son. Kise’s actions demonstrate how individuals who are themselves harmed by rigid social standards can become the system’s staunchest defenders, perpetuating a cycle of judgment and cruelty in a desperate attempt to secure their own place within the hierarchy.

Natsuki’s mother is a flat, static antagonist who functions as a primary agent of the novel’s exploration of The Destructive Nature of Societal Conformity. She consistently devalues Natsuki, openly calling her “hopeless” and a “disgrace” while praising her older daughter, Kise. Her favoritism is rooted in Natsuki’s perceived failure to perform the role of a “proper” girl, which the mother views as both a social liability and a personal affront. She prioritizes societal appearances above all else, and her actions are dictated by a rigid adherence to the expectations of the Baby Factory.

Her most significant act is her outright dismissal of Natsuki’s attempt to report Mr. Igasaki’s abuse. Instead of protecting her child, she blames Natsuki, claiming, “It’s only because you’ve got a filthy mind that you would think that” (53). This moment of maternal failure is pivotal, as it severs Natsuki’s final tie to conventional familial structures and forces her to retreat entirely into her self-constructed world of aliens and magical powers for survival. The mother embodies the dehumanizing force of a society that polices and punishes nonconformity.

Mr. Igasaki, Natsuki’s cram-school teacher, is a flat antagonist who represents the hidden corruption and danger within supposedly “normal” society. He uses his position of authority and his handsome appearance, which the girls admire, to groom and sexually abuse Natsuki. His actions, such as his invasive “lessons” on good posture where he touches her inappropriately and his humiliating lecture about her disposal of a sanitary napkin, are insidious forms of violation disguised as paternalistic guidance. He is a predator who thrives in a society that is quick to condemn Natsuki and Yuu’s sexual encounter but remains blind to the real threat posed by a charming adult man.

Mr. Igasaki’s murder at Natsuki’s hands is the novel’s most definitive act of rebellion. It is a violent and direct response to the violence he inflicts upon her, embodying the novel’s argument that survival sometimes requires extreme and horrific measures. His character highlights the hypocrisy of a world in which the pretense of “normalcy” conceals deep-seated depravity, and his death serves as the catalyst for Natsuki’s complete break from that world.

Uncle Teruyoshi is a minor character who represents a form of benevolent but ultimately ineffectual adulthood. Throughout Natsuki’s childhood, he is a consistently cheerful and engaging figure, fostering the children’s love for Akishina by playing with them and sharing stories about the family’s history. He is one of the few adults who treats Natsuki and Yuu with genuine warmth. However, despite his kindness, he is still a product of his society. When Natsuki and Yuu are discovered together, he participates in the adults’ “half-crazed” reaction, demonstrating that even well-meaning individuals are bound by the rigid norms of the Factory. Decades later, he expresses regret over the incident, acknowledging that the adults overreacted, but this apology comes too late to alter the course of Natsuki and Yuu’s lives. His character suggests that passive kindness is insufficient to combat the overwhelming force of societal pressure.

Natsuki’s father is a minor, static character defined by his passivity and silence. He is a spectral presence in the family, often described as gripping the steering wheel without speaking or standing “vacantly in the entrance” (10). His detachment makes him complicit in the emotional and physical abuse his wife and elder daughter inflict on Natsuki. He rarely intervenes, and when he does, it is to enforce patriarchal and societal authority through violence, as when he strikes Natsuki after finding her with Yuu. His character embodies the failure of the traditional patriarch to act as a protector. Instead of shielding his daughter from harm, he abdicates his responsibility, prioritizing quiet conformity and the avoidance of domestic conflict over his child’s well-being.

Shizuka is a minor character, Natsuki’s childhood friend. A flat and static character, she represents the ideal member of the Baby Factory. From a young age, she is preoccupied with fitting in, focusing on boys, cute clothes, and other socially acceptable interests. As an adult, she successfully fulfills her role by marrying and having children. She functions as a friendly envoy of societal expectations, gently but persistently probing into Natsuki’s childless marriage and offering unsolicited advice on daycare and infertility treatments. Her collusion with Natsuki’s mother to stage an intervention about Natsuki’s “abnormal” marriage demonstrates how conformity is enforced not just by family but through peer relationships. Shizuka illustrates the ordinary, seemingly benign face of the pressure to conform.