Love in Disguise (Korean: 나의 유죄인간) is an ongoing South Korean workplace romantic comedy television series starring Yim Si-wan, Seol In-ah, Kim Jung-hyun, and Yeonwoo. Based on the web novel Why You Don't Know It's a Girl? by Lee A-yeon and Ryu Do-ha, the series tells the story of a former special forces officer turned detective who disguises herself as a man and goes undercover as the personal secretary and bodyguard of a chaebol heir suspected of murder. It premiered on tvN on October 19, 2026, and airs every Monday and Tuesday at 20:50 (KST). It is also available for streaming on Amazon Prime Video.
Contents
Synopsis
Yoon Yi-jun is the successor of the Taegang Group who isolates himself at home after becoming the prime suspect in his former secretary's mysterious murder. To solve the high-profile case, Kang Jae-hee, a skilled police detective and former special forces operative, goes undercover by cross-dressing as a man to infiltrate his inner circle. She is hired as Yi-jun's male secretary and personal bodyguard. As they work together, Yi-jun's erratic and demanding behavior conflicts with Jae-hee's covert investigation. While operating within the conglomerate, Jae-hee begins to develop genuine romantic feelings for Yi-jun, complicating her undercover mission.
Cast and characters
Main
Yim Si-wan as Yoon Yi-jun
A third-generation chaebol who becomes a prime suspect in a murder case at his company and goes into hiding. His life changes when he hires a new assistant.
Seol In-ah as Kang Jae-hee
A detective from a special forces unit who poses as a man and goes undercover as Yi-jun's personal secretary to investigate him.
Kim Jung-hyun as Kim Si-hyun
A lawyer in the legal team of Taegang Group and Yi-jun's best friend.
Yeonwoo as Lee Hye-jung
Secretary to the Chairman of Taegang Group.
Supporting
Jeong Han-seol as Jeong Da-woon
Yi-jun's secretary.
Kim Do-yoon as Park Min-hwan
Taegang Group Accounting Team Manager.
Jung Yoo-min as Han Eun-young
Yi-jun's secretary and Cabinet Murder Case Victim.
Kim In-kwon as Park Bong-i
Criminal Investigation Mobile Unit Special Investigation Team Leader.
Kim Ki-bang as Jeong Wan-gu
Sergeant of the Special Investigation Team, Mobile Criminal Investigation Unit.
Nam Hae-jun as Kim Seok-jin
Inspector of the Special Investigation Team, Mobile Criminal Investigation Unit. He is Jae-hee's direct senior.
Ahn Sang-woo as Ma Hee-do
Criminal Investigation Mobile Unit Superintendent.
Choi Jin-ho as Yoon Tae-sik
Taegang Group Chairman and Yi-jun's father.
Hong Eun-hee as Yoon Mi-jin
Taegang Retail CEO and Yi-jun's eldest sister.
Park Ah-in as Yoon Na-jung
Taegang Group Executive Director and Yi-jun's second older sister.
Production
Development
Love in Disguise is based on the Kakao Page web novel and webtoon Why You Don't Know It's a Girl? by Lee A-yeon and Ryu Do-ha, produced by CJ ENM Studios and Pitapat Studio, directed by Park Dan-hee, and written by Moon Soo-jung. The series' Korean title was originally (여자인 걸 왜 모르지?; Yeojain geol wae moreuji?), then changed to (그놈은 예뻤다; Geunomeun yeppeotda), before being finalized as (나의 유죄인간; Naui yujoeingan).
The script reading took place on December 17, 2025.
Casting
In October 2025, Yim Si-wan and Seol In-ah were in talks to star. The next month, Kim Jung-hyun was cast to star, while Yeonwoo and Kim In-kwon were reportedly considering. By December 2025, Yim and Seol were confirmed to lead the series.
Filming
Principal photography began in mid-December 2025, and concluded in June 2026.
Release
Love in Disguise premiered on tvN on October 19, 2026, airing every Monday and Tuesday at 20:50 (KST). It is also available for streaming on Amazon Prime Video.
