“Life is pain.” — Nobuyuki Syamoto

Unflinching, subversive, and dripping in corrosive dark humor, Sion Sono’s Cold Fish (2010) doesn’t just showcase Japan’s taste for genre-bending horror—it rips open the underbelly of polite society and exposes what writhes beneath. If I Saw the Devil was a descent into the abyss of revenge, Cold Fish is a fever-dream trek through manipulation, depravity, and the most repressed corners of the psyche. Built around the crucible of violence and sex, Sono’s film dares viewers to question not only the shape of evil, but whether the forces that awaken it could be lurking in anyone.

Before Cold Fish, Sono had already established himself as a subversive force in horror with his earlier film Suicide Club (2001), which helped him gain a loyal cult following and introduced him to the genre scene at large as an innovative and provocative filmmaker unafraid to challenge conventions. With Cold Fish, Sono refined his style, offering a tighter, more psychologically driven narrative that accelerates the intensity while probing deep societal anxieties.

Inspired by the real-life Saitama serial murders of the 1990s, committed by dog breeder Gen Sekine and his common-law wife Hiroko Kazama, Cold Fish draws chilling authenticity from these events. Sekine and Kazama ran a pet shop and poisoned several customers before dismembering their bodies to conceal the murders. Sono reimagines this disturbing history by transforming the pet shop into a tropical fish store and fictionalizing details while preserving the core themes of manipulation, complicity, and violence.

The story opens with Nobuyuki Syamoto, the definition of a beaten-down everyman: a tropical fish shop owner whose daughter openly hates her stepmother, whose marriage is half-drowned in silent resentment, and who drifts through life as little more than a shadow. From the outset, Syamoto’s passivity sets a tremulous undertone—terrible things are happening, but he isn’t doing much to stop them. That changes the moment his daughter Mitsuko is caught stealing and rescued by the charismatic Yukio Murata, proprietor of a flashier fish store. Murata’s manners and generosity are overwhelming, almost caricatured, yet there’s an edge of anticipation: something is amiss, and Sono lets the feeling gradually curdle beneath his gentle facade.

Murata’s initial charm morphs into coercive control as he manipulates the Syamoto family into his orbit. When Syamoto is coerced to become Murata’s “business partner,” the narrative takes its first graphic, kinetic turn: a sales pitch for a rare tropical fish goes lethally wrong. Murata poisons a buyer in cold blood, then erupts into violence, forcing Syamoto and his wife into complicity by helping dispose of the body. The shift is immediate and nightmarish—the performance by Denden (Murata) snaps from quirky salesman to a near-mythical monster, as terrifying for his unpredictability as for his casual approach to killing.

From here, Cold Fish dives into a spiral of murder, sexual domination, and psychological torture. Murata and his partner Aiko have murdered dozens, perfecting the art of erasing their victims. As the body count rises, Sono’s camera remains hauntingly restrained: eschewing frantic cuts for long takes, keeping his characters center-frame, locking viewers in Syamoto’s dread-soaked POV. We are forced to witness every mechanical step in the pair’s routine—the body disposal, the literal scattering of ashes, the casual cruelty.

What makes Cold Fish such a disturbing experience is not merely the gore (though the final act is blood-soaked chaos), but the way deviance is normalized, even made bureaucratic. Murata’s operation feels part nightmare, part dull corporate job. This banality breeds horror. At times, Sono punctuates scenes with black comedy: surf rock tunes play in the background as mutilated bodies are processed in Murata’s shop, and his wife’s participation has a twisted, deadpan humor that makes the violence doubly unsettling.

Syamoto’s trajectory is the film’s secret weapon. By trapping us in his perspective, Sono draws out the uncomfortable reality of learned helplessness, craven compromise, and the latent violence beneath a repressive facade. Syamoto isn’t a hero or anti-hero, but a study in desperation and dissolution. His initial submission slowly ferments into rage, and when he finally snaps, the violence is primal and cathartic—a vengeance that feels less like triumph and more like an act of obliteration. Instead of a neat moral arc, Sono’s script is obsessed with the ambiguity of retribution: what festers beneath apathy, what trauma does when left unaddressed, and what the need to act breeds when suppressed for too long.

This thematic preoccupation connects Cold Fish to the likes of I Saw the Devil: both movies use revenge not as justice, but as a mirror for corruption—how far can the ordinary man go before he becomes indistinguishable from the monsters tormenting him? Sono’s film is ultimately more nihilistic, using social commentary as a subtle undertow, with critiques of Japanese conformity, sexuality, and family decaying beneath the surface. The result is a film that is both emotionally exhausting and intellectually provocative.

Technically, Cold Fish offers Sono at his most focused. The cinematography is subtle but relentless, with natural camera movement amplifying character reactions rather than indulging in spectacle. The use of Mount Fuji as a backdrop for scenes of violence is striking and effective. Costume, color palette, and setting all speak of an ordinary world slowly overtaken by surreal terror. The score plays off these moments, with music choices ranging from nervy tension to surf-rock irony.

The performances are uniformly superb. Denden is magnetic as Murata—making each mood shift obvious, unpredictable, and horrifying. Mitsuru Fukikoshi’s portrayal of Syamoto is raw, fragile, and ultimately explosive. The supporting cast amplifies the film’s extremes without ever feeling cartoonish. Sono pushes them to the edge, finding both tragedy and queasy humor in their unraveling. The sound design, especially in scenes of dismemberment and violence, is overwhelming and intense—forcing the audience into a sensory trap that mirrors Syamoto’s psychological implosion.

Yet Cold Fish isn’t just an exercise in gore or cruelty—it’s an autopsy of repression, cowardice, and compulsion, watched through the lens of a culture known for its traditions of obedience. The film asks what drives people to murder, what keeps them silent, and what happens when those limits are breached. It never gives viewers easy sympathies or clean answers, and the ending is deliberately unnerving—Syamoto’s transformation is complete, but it isn’t heroic, nor is it redemptive.

For some, the film’s length and relentless tone will be too much. Others have pointed out its over-the-top final act, and some feel the excessive violence is hard to justify. However, these very qualities are what cement Cold Fish as a significant work in contemporary Japanese horror—it’s the sort of movie that claws at you for days, sticking in the brain with its grim humor and powerful sense of unease. Like I Saw the Devil, it’s less about catharsis than about exposing the permanent scars left by evil and revenge, and the horrifying possibility that what lurks under the surface of normality is just waiting for an invitation to come out.

Ultimately, Sion Sono’s Cold Fish is an important piece of modern horror—not simply for its brutality, but for its relentless psychological excavation and perverse humor. By channeling the real Saitama serial murders into a study of psychological torment and complicity, Sono creates a film that is designed to provoke, to disturb, and to make audiences ask where the boundaries of morality might finally break. For genre fans, it’s a bracing, unforgettable experience; for those who approach with caution, it’s both a warning and an invitation to glimpse the heart of darkness just beneath the surface.