In Our Prime
In Our Prime (Korean: I-sang-han Na-ra-eui Su-hak-ja; lit. Mathematician in Wonderland) is a 2022 South Korean drama film directed by Park Dong-hoon.[1][2]
The film stars Choi Min-sik as Lee Hak-seong, a North Korean defector and former mathematical genius reduced to working as a security guard at an elite private high school, and Kim Dong-hwi as Han Ji-woo, a socially isolated student struggling academically and financially.[3][4]
Released theatrically on March 9, 2022, it runs for 117 minutes and centers on the unlikely mentorship where Hak-seong teaches Ji-woo advanced mathematics, risking exposure of his past amid school pressures and societal prejudices against defectors.[2][5] The narrative highlights the intense academic competition in South Korean elite institutions and the challenges faced by North Korean refugees integrating into society, drawing from real-world dynamics of defection and hidden expertise.[5]
Produced amid the COVID-19 pandemic with filming from late 2019 to early 2020, the film received praise for its emotional depth and Choi Min-sik's performance, achieving a 6.8/10 rating on IMDb from over 1,200 users, though it underperformed at the box office due to delayed release.[6][7]
Notable for portraying mathematics as a redemptive force and critiquing class divides in education, In Our Prime stands as a character-driven story emphasizing perseverance and human connection over spectacle.[1][5]
Production
Development and pre-production
The screenplay for In Our Prime was written by Lee Yong-jae, a former journalist and fund manager who drew inspiration from fragmented real-life events, including the death of a North Korean defector doctor, a teacher leaking exam answers, and a gifted student abandoning college entrance exam preparation. These elements coalesced into a narrative framework centered on a North Korean defector mathematician, with the protagonist's backstory predating the full plot conception. Lee selected mathematics as the core motif due to its perceived eternity and absolute truths, influenced by readings on mathematical history and admiration for figures like Grigori Perelman, Ree Rim-hak, and Paul Erdős, whose eccentric brilliance and reclusive tendencies informed the lead character Lee Hak-sung.[8][9] During development, Lee envisioned actor Choi Min-sik for the role of Hak-sung, a choice aligned with the character's intellectual depth and isolation, and incorporated themes of courageous questioning akin to solving unsolved theorems, emphasizing mutual emotional support among societal outcasts. The script underwent revisions, with approximately 30 scenes excised—primarily from the latter half, including an entire subplot involving Ji-woo's friend—to fit commercial runtime constraints of around two hours. Director Park Dong-hoon, in pre-production, found thematic resonance in BTS member Jungkook's 2018 track "Euphoria," whose hopeful, dawn-greeting energy shaped his vision for student Ji-woo's arc and influenced casting; after auditioning over 250 actors, Park selected Kim Dong-hwi for embodying a confident, adventurous spirit matching the song's vibe.[8][9][10] Pre-production was handled by Joy Rabbit, with Showbox as distributor, focusing on integrating mathematical proofs and music to underscore the story's intellectual and emotional layers. Principal photography commenced on December 2, 2019, and wrapped on March 12, 2020, allowing for authentic depictions of elite high school dynamics and defector challenges amid South Korea's competitive education system.[11][2]Casting
Director Park Dong-hoon cast veteran actor Choi Min-sik in the lead role of Lee Hak-sung, a reclusive North Korean defector and former mathematical prodigy reduced to working as a high school security guard. Park, who described himself as a devoted fan of Choi's performances, stated that the mere prospect of Choi embodying the character generated significant anticipation during pre-production.[12][13] The pivotal role of Han Ji-woo, a high school outcast who has abandoned mathematics amid academic pressures, went to Kim Dong-hwi following rigorous auditions that drew over 250 applicants per spot.[14][15] Kim's selection was confirmed in late 2019, highlighting his emerging presence after supporting roles in films like Nomad and Peter Pan's Dream.[16] Supporting cast included Park Byung-eun as the school's mathematics teacher Kim Geun-ho, Park Hae-joon, and Jo Yoon-seo, who altered her appearance with a short haircut to suit her character's demands.[2] A script reading session took place in November 2019 with the principal actors, solidifying character interpretations ahead of filming commencement on December 2, 2019.[17] The ensemble drew on established performers to underscore the film's exploration of intellectual isolation and mentorship dynamics.[18]Filming and technical aspects
Principal photography for In Our Prime took place in Seoul, South Korea, focusing on urban school environments and everyday settings to reflect the protagonists' social isolation and intellectual pursuits.[6] Cinematographer Park Hong-yeol oversaw the visual capture, employing techniques suited to the drama's introspective narrative, including close-ups during mathematical teaching sequences and wider shots of the high school campus.[19] Editing by Kim Sun-min shaped the 117-minute film, pacing the story to balance character development with explanatory math segments.[19][2] Sound supervision was led by Lee Seung-yup, with design elements emphasizing ambient school noises and subtle cues in problem-solving scenes.[19][20] The score, composed by Lee Ji-soo, incorporated minimalist motifs to underscore themes of discovery and resilience.[19] Limited visual effects were integrated by artist Kim Jae-hoon, primarily for enhancing abstract mathematical concepts without dominating the realistic tone.[20]Plot
In Our Prime centers on Han Ji-woo (played by Kim Dong-wi), a high school student from a low socioeconomic background who attends the prestigious Donghun Academy via a welfare scholarship program. As an outcast among his affluent peers, Ji-woo endures bullying and academic struggles, particularly in mathematics, where his poor performance in a key competition jeopardizes his enrollment.[21][5][22] One night, while evading school authorities, Ji-woo encounters Lee Hak-sung (Choi Min-sik), the school's unkempt night security guard responsible for maintenance. Hak-sung, a North Korean defector concealing his identity, was once a renowned mathematician in the North but now lives in anonymity in South Korea to safeguard his remaining family. During an impromptu discussion, Ji-woo discovers Hak-sung's exceptional mathematical aptitude and begs him for private lessons.[2][6][4] Hak-sung initially resists but eventually mentors Ji-woo in after-hours sessions, employing intuitive, practical methods to demystify complex concepts. This guidance transforms Ji-woo's skills and confidence, enabling him to compete in a national mathematics olympiad. However, their unorthodox partnership draws scrutiny from school officials wary of the guard's influence, while Hak-sung grapples with resurfacing elements of his defection and past achievements. The narrative explores their evolving mentor-student dynamic amid institutional pressures and personal revelations.[23][24][25]Cast and characters
Choi Min-sik stars as Ri Hak-sung, the reclusive security guard at a prestigious high school who possesses extraordinary mathematical talent but conceals his past as a North Korean defector and former prodigy.[6] Kim Dong-hwi portrays Han Ji-woo, a bullied high school student from an impoverished family who struggles academically, particularly in mathematics, and forms an unlikely mentorship with Hak-sung to improve his skills.[6] Park Hae-joon plays Ahn Gi-chul, a faculty member involved in the school's dynamics amid the unfolding events. Park Byung-eun appears as Kim Geun-ho, contributing to the supporting ensemble of teachers and school staff. Jo Yoon-seo depicts Park Bo-ram, a character interacting within the high school environment and student interactions.| Actor | Character |
|---|---|
| Choi Min-sik | Ri Hak-sung |
| Kim Dong-hwi | Han Ji-woo |
| Park Hae-joon | Ahn Gi-chul |
| Park Byung-eun | Kim Geun-ho |
| Jo Yoon-seo | Park Bo-ram |