The upcoming thriller Sister, starring Jung Ji-so, Lee Soo-hyuk, and Cha Joo-young, has officially confirmed its theatrical release date for January 28, 2026.
On December 22, distributors Studio Santa Claus Entertainment and CJ CGV announced the release schedule while unveiling the film’s first official poster. Directed by Jin Sung-moon, Sister is a tense psychological thriller that revolves around a kidnapping scheme driven by money, secrets, and fractured relationships.
A Kidnapping Fueled by Family and Betrayal
Sister follows Haeran (Jung Ji-so), who kidnaps her half-sister Sojin (Cha Joo-young) in a desperate attempt to secure a large ransom. Behind the scenes is Taesu (Lee Soo-hyuk), the mastermind who meticulously orchestrates the crime. As Sojin fights to escape captivity, long buried truths begin to surface, turning the into a high stakes psychological battle. Set largely within a confined space, the film promises intense suspense, claustrophobic tension, and sharp psychological warfare between the three characters.
Jung Ji-so’s Emotional Transformation
Jung Ji-so, who first captured public attention as Da-hye in Parasite, has steadily built a strong acting portfolio through projects such as The Cursed and The Glory. In Sister, she takes on the role of Haeran, a young woman driven to extremes to pay for her younger sibling’s surgery. By portraying Haeran’s inner conflict, emotional fractures, and shifting motivations, Jung is expected to deliver a layered performance that anchors the film’s narrative.
Lee Soo-hyuk as a Cold Blooded Mastermind
Lee Soo-hyuk transforms into Taesu, the calculated architect of the kidnapping. Known for his commanding presence and restrained acting style in works like Queen Woo and S-Line, Lee brings a chilling calmness to a character who controls every situation from the shadows. His portrayal is expected to mark one of his most intense villain roles to date.
Cha Joo-young as the Unpredictable Variable
Cha Joo-young, who rose to prominence through The Glory and has since earned praise for her performances in Won-gyeong and Lobby, plays Sojin, the unsuspecting victim. Abducted by a sister she never even knew existed, Sojin becomes a key variable who threatens to unravel the kidnappers’ carefully laid plan. Her performance is set to balance vulnerability with quiet strength, adding emotional depth to the thriller.
A Poster That Sets the Tone
The newly released poster features the starkly contrasting expressions of the three leads: Haeran’s tense gaze, Taesu’s enigmatic calm, and Sojin’s visible fear. Accompanied by the haunting tagline, “Today, I kidnapped my sister,” the poster hints at a story that goes beyond a simple crime one rooted in family, desperation, and hidden truths.
Editor’s Notes
What makes this story compelling is not just the premise of a kidnapping.
It is the way the conflict is framed within a family dynamic.
By centering the narrative around a half-sister relationship, the film moves beyond a typical thriller setup and into something more psychologically layered. The tension is not only about escape or survival, but about unresolved emotions, hidden histories, and moral ambiguity between characters who are connected in unexpected ways.
The structure of the story also stands out. With much of the film set in a confined space, the focus shifts from action to performance. This places greater weight on the actors’ ability to carry tension through expression, dialogue, and silence.
Each casting choice supports that direction.
Jung Ji-so brings emotional instability and internal conflict, Lee Soo-hyuk adds controlled intensity, and Cha Joo-young introduces unpredictability. Together, they create a dynamic where the suspense comes from shifting power rather than constant movement.
That is what gives the film its edge.
It is not driven by what happens next, but by how the characters reveal themselves under pressure.