Following the global popularity of Kill Boksoon, Netflix expands its assassin-verse with Mantis (Samagwi), a spinoff that shifts the spotlight onto a new generation of contract killers. Directed by Lee Tae-sung, the film blends brutal combat sequences with character-driven drama, creating a story that balances tension, dark humor, and human vulnerability. While Mantis may not match the razor-sharp edge of its predecessor, it delivers a layered narrative centered on loyalty, rivalry, and survival in a collapsing industry.
Story
The film wastes no time pulling the audience in. The cold open immediately introduces Han-ul (Yim Si-wan), the assassin known as “Mantis,” setting the tone with a mix of slick action and tongue-in-cheek narration. Picking up after the death of Min-kyo, the powerful CEO from Kill Boksoon, the organization that once dictated order in the assassin world—MK Entertainment—crumbles into chaos.
In the resulting power vacuum, young assassins scramble to stake their claims. Han-ul, overly confident in his reputation, returns to Korea assuming his past success will guarantee future stability. But for his childhood friend, Jae-yi (Park Gyu-young), opportunities are scarce. Cast out of MK Entertainment, she is nearly blacklisted, struggling to reassert herself in a brutal industry where names carry more weight than talent.
Motivated both by pride and companionship, Han-ul creates “The Mantis Company” with guidance from his retired mentor Dokgo (Jo Woo-jin). But as competition intensifies, rivalries flare, and a dangerous investor (Choi Hyun-wook) enters the picture with his own obsession, Han-ul begins to realize that strength alone won’t secure survival. The heart of the story is less about kills and contracts, and more about fractured relationships as Han-ul and Jae-yi’s bond is tested to its breaking point.
Performances
At the core of Mantis is the dynamic between Yim Si-wan and Park Gyu-young. Yim shines as Han-ul, channeling charisma tinged with arrogance—a performance that feels deliberate, illustrating a man clinging to past glory. Meanwhile, Park Gyu-young steals the spotlight in several action sequences, embodying Jae-yi’s simmering frustration from years of comparison. Her evolution from overlooked assassin to formidable rival is one of the film’s most compelling arcs.
Jo Woo-jin delivers a strong supporting turn as Dokgo, whose quiet wisdom fills the void left by Min-kyo. His mentorship ties past and present together, adding emotional weight and drawing parallels between generations of assassins. By contrast, Choi Hyun-wook’s investor character feels undercooked—introducing tension but lacking the depth necessary to make his arc truly impactful.
Behind the Scenes
Director Lee Tae-sung’s vision focuses heavily on narrative-driven violence. Unlike gratuitous action fare, every fight has meaning, whether it’s revealing character psychology or escalating emotional stakes. While the choreography is effective, it lacks some of the finesse and spectacle that made Kill Boksoon visually iconic. Still, the stripped-down action reinforces the theme of younger killers still finding their footing, which makes sense within the story.
Notably, the film touches on broader, relatable concepts—like the struggles of gig work and competition among freelancers—using the assassin world as a metaphor. Unfortunately, these themes could have been further developed to provide more societal commentary, which would have strengthened the spinoff’s identity.
Final Verdict
Mantis may not reach the legendary status of Kill Boksoon, but it succeeds as a grounded continuation of its universe. Its strongest asset lies in the relationship and rivalry between Han-ul and Jae-yi, which provides emotional depth beyond the gunplay and sword fights. While pacing hiccups and certain underwritten characters hold it back slightly, the final act ties everything together with an intense and satisfying showdown.
Overall, Mantis proves to be a solid—if slightly uneven—spinoff. For fans of Kill Boksoon, it’s worth watching for its character-driven drama, sharp performances, and meaningful expansion of Netflix’s assassin world.
Mantis is now streaming exclusively on Netflix.
