Strangers from hell is a claustrophobic psychological thriller where a young intern moves to a cheap, creepy dormitory in Seoul. He discovers his fellow tenants are a bizarre, terrifying cult of cannibalistic serial killers.

Yoon Jong-woo is a young aspiring writer who moves from the countryside to Seoul for an internship. Played by Im Si-wan, he begins as an ordinary, empathetic man whose financial struggles force him into a creepy dormitory. Through severe psychological manipulation and isolation, he gradually descends into paranoia, repressed rage, and murderous insanity. Main character

Seo Moon-jo is a charismatic dentist who secretly leads a terrifying cult of serial killers. He serves as the primary antagonist of Strangers from Hell, embodying pure, calculative evil beneath a flawless, polite professional facade.

Eom Bok-soon is the deceptively warm and maternal landlady of Eden Dormitory who serves as the foundational root of evil in Strangers from Hell. Played brilliantly by Lee Jung-eun (widely recognized for her role in Parasite), she uses a doting, religious facade to mask her past as a black widow and her current status as the caretaker of a serial killer cult.

Yoo Gi-hyeok (played by Lee Hyun-wook) is a cold, eerie resident of Room 302 who serves as the initial, terrifying "boss" figure of Eden Dormitory. When the protagonist Yoon Jong-woo first moves into the building, Gi-hyeok is introduced as the most intimidating neighbor, often seen wearing long sleeves in the dead of summer to hide his dark secrets.

Hong Nam-bok (played by Lee Joong-ok) is the deeply unsettling, perverted resident of Room 313 in Strangers from Hell. If the other villains in the Eden Dormitory represent calculated, predatory evil, Nam-bok represents base, filthy, and unhinged degradation. He plays a major role in wearing down Yoon Jong-woo’s psychological defenses simply by being an inescapable, gross nuisance. Wears a ankle monitor, is a sex offender, often stares at jong-woo, known for being the glaring stalker

Byeon deuk-jong is the deeply unnerving, giggling resident of Room 306 in Strangers from Hell. Played by Park Jong-hwan, he is half of the dormitory's terrifying twin duo, recognizable by his shaved head and a distinctive, stuttering laugh that serves as a constant acoustic nightmare for the protagonist.

Byeon Deuk-soo is the articulate but highly aggressive resident of Room 307 who forms the second half of the dormitory's terrifying twin duo. Played by Park Jong-hwan, he is the identical twin brother of the giggling, stuttering Byeon Deuk-jong.

Kang Seok-yoon is the friendly, optimistic newcomer who briefly serves as Yoon Jong-woo’s sole ally and a tragic symbol of innocence within the Eden Dormitory. Played by Noh Jong-hyun, he moves into the hostel mid-way through the series, bringing a rare spark of normal, youthful energy into an otherwise suffocating and psychotic environment.

So Jung-hwa is a dedicated, highly intuitive patrol officer who serves as the moral compass and primary investigator of the outside world in Strangers from Hell. Played by actress Ahn Eun-jin, she is one of the very few characters who treats the bizarre occurrences surrounding the Eden Dormitory with the serious attention they deserve, making her the protagonist's most critical lifeline.