Mantis: Release date news, cast details, streaming details, and more about the upcoming Korean movie starring Squid Game’s Im Si-wan

Mantis arrives swinging a blade through the underworld of killers, a continuation of the violent mythology first unveiled in Kill Boksoon. The world of contract killers is governed by rules, and rules are everything until they collapse. Netflix’s new Korean film embraces that collapse with blood-red imagery, a new generation of rivals, and a story that pushes the assassin universe into darker, hungrier territory.

Where the first film centered on a mother who balanced family and murder, this spin-off shifts to a man returning from exile, prepared to fight his way back to the top. Mantis is not just a companion piece. It cuts deeper into a world where ambition becomes a weapon and legacy is written in blood.

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Release date and global premiere

The film premieres on September 26, 2025, streaming exclusively worldwide on Netflix. The date was revealed alongside the first teaser and official poster in August 2025.

Like Kill Boksoon, there won’t be a theater window. This is a Netflix Original designed for global rollout, dropping simultaneously across regions so fans everywhere step into the chaos at once.

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A cast sharpened for combat

At the heart of the story is Han-ul, codenamed “Mantis,” played by Im Si-wan. In Kill Boksoon, Cha Min-kyu casually mentioned that Mantis was on vacation. That small detail now blooms into an entire film. Si-wan takes on a role unlike his past, shedding innocence for cold calculation.

It’s also important to remember his recent role in Squid Game. He played Myung-gi, a character whose actions drew anger and disdain from many viewers. That reputation adds an extra charge to his casting here, making his turn as a deadly assassin even more intriguing. Surely his experience with Strangers from Hell will help make him shine here.

Han-ul collides with Jae-yi, played by Park Gyu-young, his former trainee partner and now his rival. Their relationship mixes trust with betrayal and affection with violence. Park’s growing global profile, after Sweet Home and Celebrity and with her involvement in the second and third seasons of Squid Game, guarantees attention.

Then there’s Dok-go, embodied by Jo Woo-jin, a retired legend who reenters the game and destabilizes the balance. His presence carries the gravitas of experience, the counterweight to younger killers hungry for power.

Even in death, Cha Min-kyu leaves his mark. Seol Kyung-gu lends his voice to the teaser, reciting the old rules of MK ENT. His echo links Mantis back to its predecessor while showing that the old order still haunts the new one.

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Streaming details

Like its predecessor, Mantis is a global Netflix exclusive. There won’t be staggered schedules or limited runs. Netflix wants one platform, one launch, one global conversation.

The platform is investing heavily in Korean genre cinema, building its own assassin universe to stand beside franchises like John Wick. With Mantis, the plan is clear: the film will drop in every country at once, reigniting the chatter that made Kill Boksoon a surprise international hit.

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Plot and continuity

Han-ul returns from his long break expecting order, but he finds chaos. The industry of assassins is fractured. The rules are gone, alliances shattered, and colleagues are now rivals.

He steps into a battlefield where Jae-yi challenges him directly, and Dok-go reemerges, unwilling to stay retired.

This is both a continuation and an inversion. Kill Boksoon told the story of Gil Bok-soon, a mother balancing maternal instinct with contract killing. Mantis tells the story of a man locked in a fight for succession and supremacy. Both films are fascinated by rules and betrayals, but each protagonist embodies a different way of surviving.

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Trailer, poster, and visual style

The teaser begins with Cha Min-kyu’s voice reminding killers of the rules, even as the visuals show a world where those rules mean nothing. Then comes the unforgettable image: Han-ul in a bright red suit, walking like blood made flesh, holding a sickle-shaped blade.

The footage cuts between ruthless duels and verbal sparring. Jae-yi taunts him, asking if she’s finally above him. He responds coldly,

“So you wanted to kill me?”

Their exchanges promise a rivalry as intimate as it is lethal.

The poster drives the point home. The slogan declares, “A New Era of Rising Killers.” What once belonged to veterans like Cha Min-kyu now passes to ambitious newcomers, ready to stain their hands deeper than ever.

[In a world of killers where all the rules have collapsed, who will rise as No. 1?

A new era of rising killers begins. Netflix film Mantis premieres September 26. Only on Netflix.”]

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Production background

Mantis is directed by Lee Tae-sung in his feature debut, supported by Byun Sung-hyun, writer-director of Kill Boksoon, who co-wrote the script. This partnership ensures continuity in tone while leaving space for new energy.

Filming ran from August to December 2024, produced by SEE AT Film. The extended shoot reflects complex choreography and heavy training. Si-wan trained in blade combat, while Park refined her close-quarters skills. The result promises action scenes that match the intensity of Kill Boksoon while adding their own flavor.

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Building the assassin universe

When Kill Boksoon premiered at the Berlin Film Festival, critics quickly compared it to John Wick. The similarities were clear: codes of conduct, an underground guild, strict penalties. Yet Kill Boksoon stood out for its cultural texture and its emotional depth.

It scored 79 percent on Rotten Tomatoes and logged 63 million viewing hours in its first weeks on Netflix. Those numbers proved the assassin world could become a franchise. Mantis is the payoff, a direct continuation that expands the mythology and lets new characters step into the spotlight.

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Curiosities fans are asking about Mantis

Is there a connection to Queen Mantis, the SBS drama premiering earlier in September? The answer is no. Netflix’s Mantis is a film, not a series, and it belongs to the Kill Boksoon universe, not the world of television dramas.

What about the meaning of the name? Promotional materials highlight how the syllables of “Mantis” echo words for death, demon, and ghost in Korean. Combined with his crimson suit and sickle weapon, the codename becomes more than insect imagery. It’s a warning.

Will Gil Bok-soon appear? All signs point to no. This film centers on Han-ul. Her presence lingers only in reputation and the mention of her past, while Cha Min-kyu’s voice ties the worlds together.

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Expectations and anticipation

The teaser has already stirred excitement. Fans are debating the red suit, the sickle, and the sharp exchanges between rivals. International outlets are highlighting the Squid Game connection, with Si-wan and Park reunited in another Netflix production.

Critics expect Mantis to build on the balance of style and substance that made Kill Boksoon stand out. Audiences are watching closely to see if Netflix’s assassin world can grow into a long-running universe.

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The blade’s edge

Mantis is both successor and disruptor. It respects the foundation of its predecessor while showing what happens when the structure breaks apart. It carries forward continuity while telling a fresh story about three killers colliding at the edge of survival.

On September 26, 2025, when the film arrives worldwide, viewers will finally see which of them claims the crown. Until then, questions sharpen the anticipation. Who will rise as number one? How deep can loyalty cut before it turns to betrayal? And how far will Netflix go in building a Korean universe of assassins that can rival the giants of global cinema?