Heart Signal

Heart Signal is a South Korean dating reality television show distributed by Channel A. Season 1 of the show aired in 2017, followed by season 2 in 2018, season 3 in 2020 and season 4 in 2023. Based on the cast members of Heart Signal, a new program named Friends was also produced.

Overview
The reality show follows eight people living together for one month as they get to know each other and go on dates. Every night, each cast member sends an anonymous text message to another cast member to show their romantic interest. However, they are not allowed to directly confess their love. Meanwhile, a panel of celebrities and experts watches the show, analyzing the cast members' actions and trying to predict who will text who.

Panelists
Season 1
 * Yoon Jong-shin
 * Lee Sang-min
 * Kim Eana
 * Yang Jae-woong
 * Shim So-young
 * Shindong (Super Junior)

Season 2
 * Yoon Jong-shin
 * Lee Sang-min
 * Kim Eana
 * Yang Jae-woong
 * ONE
 * Soyou

Season 3
 * Lee Sang-min
 * Kim Eana
 * Yang Jae-woong
 * Han Hye-jin
 * Yoon Shi-yoon
 * P.O (Block B)

Season 4
 * Yoon Jong-shin
 * Lee Sang-min
 * Kim Eana
 * Kim Choong-gi
 * Kang Seung-yoon (Winner) -> Kim Jin-woo (Winner)
 * Mimi (Oh My Girl)

Cast members
Season 1  Season 2

Season 3

Season 4

Controversies
Season 1

In 2019, Heart Signal cast member Kang Sung-wook was sentenced to five years in prison for sexually assaulting a woman in August 2017. Fellow cast member Jang Cheon reportedly initially served as Kang's lawyer in the case but resigned after six days. Kang's sentence was reduced to 30 months in prison in 2020.

Season 2

Heart Signal 2 cast member Kim Hyun-woo was arrested for drunk driving in April 2018 while the show was airing.

Season 3

After the cast members of Heart Signal 3 were publicly announced, a woman accused cast member Lee Ga-heun of bullying classmates. Cast member Cheon An-na was also accused of bullying. The show's producers denied the allegations.

While the show was airing, another woman told the media that cast member Kim Kang-yeol had kicked her in the stomach at a nightclub in January 2017. Kim admitted to the incident and apologized on social media.

In May 2023, Yongsan Police Station in Seoul applied for an arrest warrant for Seo Min-jae on charges of violating the Narcotics Control Act. This suspicion was raised when Seo Min-jae made an SNS post revealing that she and her then boyfriend, Nam Tae-hyun, took methamphetamine in August 2022. In September 2022, the police finally collected the hair and urine of Seo Min-jae and Nam Tae-hyun, who were suspected of violating the Narcotics Control Act, and requested an appraisal from the National Institute of Scientific Investigation (NFS).