Mantis – Movie Review | Netflix (3/5)

MANTIS on Netflix is a new South Korean action thriller. It’s a spin-off of the 2023 Netflix movie Kill Boksoon, but it differs quite a lot in tone, as this one is much lighter. Still entertaining, but doesn’t pack the same emotional punch. Read our full Mantis movie review here!

MANTIS is a new Netflix action thriller from South Korea (org. title: Samagwi, Korean: 사마귀). If you’ve watched the 2023 Netflix movie Kill Boksoon, then this world and several characters will be familiar, as this is a spin-off movie.

Despite being a South Korean genre production, the runtime is just shy of two hours, which is fairly short. Even compared to the original movie in this universe, which has a runtime of 2 hours and 17 minutes.

Continue reading our Mantis movie review below. You can find it on Netflix now.

A shake-up in the hired killer industry

In Mantis, the title character is an ace assassin who has chosen this insect-inspired name, which many love to ridicule him for. He is a former colleague of the brilliant killer Gil Boksoon, who was the star of the 2023 movie.

As Mantis (Yim Si-wan) returns after his European vacation, it’s to a new world. The hired killer industry has been shaken up, and a new world order needs to be established.

Could Mantis be the head of a new company with his fellow trainee (and friend, who he clearly has feelings for), Jae-yi? Well, if it were up to him alone, the two would definitely be colleagues. Jae-yi (Park Gyuyoung) is more conflicted.

And how can Dok-go (Jo Woo-jin), another legend from the world of assassins, fit in? Each of them is aiming for the spot as top killer, but only one can be the very best!

Finally, there’s the tech bro, Benjamin (Choi Hyun-wook), who also seems intrigued by this world, and wants to be included… or in charge?!

A Kill Boksoon spin-off movie

While this is a spin-off to Kill Boksoon, and very clearly plays out in the same world, it does differ quite a lot.  This 2025 movie is much lighter and uses more comedy and action rather than emotional and psychological triggers.

In fact, “psychological thriller” was a subgenre for Kill Boksoon, and it isn’t included for this 2025 spin-off movie.

Think John Wick and Ballerina, but with even bigger tonal differences. The movies take place in the same world, but feature different main characters, though still including many of the same characters and cast members as well.

Watch Mantis on Netflix now

The South Korean Netflix Original movie is directed by Lee Tae Sung and created by Byun Sung Hyun, who wrote and directed the Netflix film Kill Boksoon.

The 2023 movie was watched for over 63.3 million hours by subscribers, which equated to roughly 27.5 million Netflix views. Obviously, there was an audience for more from this assassin-fueled universe.

Despite the trailer revealing (or at the very least indicating) as much, I was a little disappointed that Mantis was so much lighter than Kill Boksoon. With South Korean production, I tend to enjoy the heavier emotional plots more.

Having said that, this is still a very entertaining genre-mix, where brilliant fight sequences are combined with a thriller and crime plot. Give it a shot and see if it’s your cup of tea.

Mantis (org. title: Samagwi) is on Netflix from September 26, 2025.

Details

Director: Lee Tae-sung
Writers: Byun Sung-hyun, Lee Tae-sung
Stars: Yim Si-wan, Park Gyuyoung, Jo Woo-jin