On the May 20 broadcast of Channel A's 'Detectives' Trade Secrets,' a touching story was revealed in which 36-year veteran actor Shin Hyun-jun searched for his teacher after 40 years, along with the shocking true story of a husband who registered his marriage to a woman 15 years his senior on his wedding day.

[Shin Hyun-jun, "Never Give Up on Your Dreams"... Finding Teacher Kim Eok-gwan After 40 Years]

On this day's broadcast, actor Shin Hyun-jun made a surprise appearance as a client. He requested help in finding his high school senior year homeroom teacher, Kim Eok-gwan.

During his school days, Shin Hyun-jun was a promising tennis player who enrolled in the Department of Physical Education at Yonsei University. At the time, teacher Kim Eok-gwan gave him heartfelt advice, saying, "Is physical education truly your dream? Even if your mind changes after entering college, never give up on your dreams."

This advice became a turning point that changed Shin Hyun-jun's life. In college, he explored the path of acting through theater and film classes and group projects, and later successfully debuted as an actor by landing the role of Hayashi in director Im Kwon-taek's film 'The General's Son.'

Currently working as a university professor nurturing the next generation, Shin Hyun-jun expressed his gratitude, saying, "A teacher is someone who helps you become the kind of mentor that students can confide in about worries they can't even share with their parents or friends." Regarding teacher Kim Eok-gwan, who is believed to be in his 80s, he revealed his earnest heart, saying, "I just hope he is alive." Whether the two will reunite will be revealed on next week's broadcast.

[Married Twice on the Wedding Day?... A Husband Who Registered Marriage with a Female Superior 15 Years Older]

Meanwhile, in the true story reconstruction segment 'Case Notebook,' the story of a female civil servant client working at a district office was introduced. The client went to register her marriage with her husband, only to discover a shocking fact belatedly. Her husband had already been registered in marriage to a female superior 15 years his senior who worked in the same department.

This female superior, who was raising three children alone, had been carrying on a secret affair with the client's husband for a long time. According to the detective team's investigation, the female superior had approached the husband, who grew up in difficult circumstances without parents and struggled with debt, by helping him with meals and daily life.

When the husband tried to end the relationship ahead of his marriage, the female superior came to his home and did not hesitate to threaten him, saying, "I'll make sure you don't get promoted." An unimaginable event occurred on the wedding day. The female superior lured the husband by claiming she had won a housing subscription for an apartment worth around 900 million won, and just before entering the wedding hall, the husband ended up signing the marriage registration form she handed him. An unprecedented situation unfolded in which he got married twice on the same day.

When the client confronted him about the truth, the husband gave a bolt-from-the-blue response: "If she had a house like this from the beginning, I never would have met you. A plus option in life appeared." As the client reported this fact to their workplace, the husband eventually faced disciplinary proceedings and went on leave.

[Studio Outrage... "Material Poverty May Be Unavoidable, But Mental Poverty Is One's Own Fault"]

Fury erupted in the studio. Defconn remarked sharply, "In the end, it all comes back to bite you," and Kim Poong gave a scathing assessment, saying, "Material poverty in childhood may have been unavoidable, but creating mental poverty as an adult is entirely his own doing."

Kim Min-soo, who appeared as a one-day detective, mentioned his experience of dating an older woman and showed empathy, saying, "If an older woman took care of me that much, I would feel it was love." However, regarding the husband's betrayal of his pregnant wife on their wedding day, he lamented, "It was a moment to think about what is more important than money."

Channel A's 'Detectives' Trade Secrets' airs every Monday at 10 PM.