The Affair Was Just the Beginning (2026)

This is the story of a young family that just recently became parents. The wife is named Kyung-hee, and her husband, Je-hoo, is an aspiring actor. Their little daughter is named Ye-ji. At first, they are struggling financially and living a tough life. Every time it rains, water leaks through the roof of their home, and their daughter is constantly sick with a cough from the dampness.

One day, Kyung-hee decides to put an end to their misery. Hearing that YouTubers can make good money, she starts a YouTube channel. Since she is an interior designer, she focuses on home decor. Je-hoo acts as her assistant. At first, they make simple videos—building soap boxes, replacing door handles, and crafting clothes hangers—and quickly reach 100,000 subscribers.

Using the money earned from YouTube, they renovate their place and gradually upgrade to larger homes over the years. Sixteen years later, they own a luxurious villa. While Kyung-hee used to film alone with her husband, she now owns her own media company and studio, managing a full team of directors, graphic designers, and camera crews. By this time, Ye-ji has grown into a teenager. Their success is truly thanks to Kyung-hee’s dedication.

One day, while filming a vlog to celebrate their move into the new villa and thanking their subscribers, they decide to introduce themselves to their new neighbor. Their neighbor turns out to be Soo-jung, a single mother living with her daughter, Min-so. Since Min-so attends the same school as Ye-ji, Kyung-hee warmly tries to make friends. However, Soo-jung acts cold and distant right from the start, despite knowing how famous Kyung-hee is. Kyung-hee soon realizes that she and Soo-jung are completely different people. Meanwhile, Min-so and Ye-ji hit it off and become best friends.

Trouble begins when Je-hoo gives Soo-jung a flirtatious look the moment they meet, and Soo-jung immediately picks up on it. Kyung-hee notices nothing. Around this time, Kyung-hee is looking for a sponsor for her upcoming major project and identifies Madam Michelle as the ideal candidate. To get close to Michelle, Kyung-hee learns that Soo-jung is actually like family to Michelle.

Kyung-hee researches Soo-jung and discovers that she runs a large cosmetic surgery clinic, which she originally founded with her ex-husband, Bu-seon. After her husband cheated on her, they divorced, and Bu-seon left behind the clinic, their home, and their daughter Min-so. Following the divorce, Soo-jung fell into depression and neglected her clinic, causing her income to drop significantly.

Kyung-hee offers to bring famous actors to Soo-jung’s clinic to boost its reputation through promotion, hoping to gain Soo-jung's trust and get an introduction to Madam Michelle. Je-hoo brings a young actor named Ji-soo to the clinic. The clinic's manager turns out to be a huge fan of Kyung-hee and promises free services if Kyung-hee visits.

While Je-hoo and Ji-soo are just close friends, people often mistake them for a couple because Ji-soo frequently clings to him. While at the clinic's rooftop, Je-hoo runs into Soo-jung, who came up to vent about her ex-husband opening a competing clinic nearby. When the rooftop door gets accidentally locked, Soo-jung carelessly throws a cigarette butt into a trash can, starting a small fire. Je-hoo panics while trying to put it out, and Soo-jung ends up spraying his face with a fire extinguisher. In that chaotic moment, Soo-jung finds herself unexpectedly attracted to Je-hoo.

As Je-hoo continues bringing celebrity clients to the clinic, business booms, and Soo-jung grows increasingly attached to him. Expressing her gratitude, Soo-jung invites Kyung-hee and Je-hoo over for dinner. There, Kyung-hee sees a picture of Soo-jung with Madam Michelle and mentions how much she wants to meet her. Soo-jung agrees to set up a meeting.

During dinner, Soo-jung openly flirts with Je-hoo under the table by touching his leg with her foot. Startled, Je-hoo drops his wine glass, cutting his hand and spilling wine on Kyung-hee's clothes. While Kyung-hee goes to the bathroom to clean up, Soo-jung wraps Je-hoo's cut finger, leading to their first intimate physical encounter. From that moment on, they begin a secret affair right behind Kyung-hee's back, while Kyung-hee remains completely oblivious, thrilled about the upcoming meeting with Michelle.

Over time, Je-hoo and Soo-jung's secret relationship deepens. Meanwhile, Soo-jung is locked in a fierce custody battle with her ex-husband, who has hired a highly competent lawyer. Min-so prefers living with her father because he supports her dream of becoming an artist, whereas Soo-jung pressures her to become a doctor. Desperate to win custody, Soo-jung decides to hire a private investigator to find dirt on her ex-husband. Je-hoo helps her find one, but stays in the background to protect his public image. The P.I. agency turns out to be run by identical twin brothers who operate a shady business.

Eventually, Kyung-hee meets Madam Michelle during a game of golf, fulfilling her goal. Meanwhile, Je-hoo is enjoying what feels like having two wives. However, Soo-jung grows possessive and jealous whenever she sees Je-hoo near other women like Ji-soo, deciding she wants him all to herself.

Around this time, Je-hoo purchases a countryside house on a large estate. Inspecting the property, they find an abandoned underground cellar and seal it up.

Kyung-hee prepares to host Madam Michelle at her house to secure a massive business investment. However, Michelle cancels at the last minute after hearing online rumors that Je-hoo is having an affair with Ji-soo, stating she cannot risk investing in a family plagued by scandal. Determined to find out the truth, Kyung-hee confronts Je-hoo that evening. Je-hoo vehemently denies any affair with Ji-soo, explaining that people misunderstood seeing them together at the clinic. Since Kyung-hee has no concrete proof, she drops the argument but secretly places a GPS tracker in Je-hoo’s wallet that night.

That very night, four major events unfold simultaneously:

1. First Event: The private investigator hired by Soo-jung gets her ex-husband's lawyer drunk and steals his phone. Looking for blackmail material to force him to throw the custody trial, the P.I. discovers horrifying videos proving the lawyer is a predator targeting minors. When the lawyer realizes his phone was taken, he chases the P.I. into the night.
2. Second Event: Je-hoo secretly visits Soo-jung at her clinic after hours. Unbeknownst to them, the clinic manager returned to pick up a forgotten item, catches them in the act, and secretly records their romantic encounter on her phone.
3. Third Event: Upset after an argument with her mother, Min-so goes for a ride with Ye-ji. Ye-ji secretly takes her father’s car keys to cheer Min-so up. While showing off her driving skills on a quiet road saved in the GPS, Min-so takes the wheel, panics, and accidentally hits a pedestrian. The person she hits is the private investigator who was running away from the lawyer.
4. Fourth Event: Thinking the man is dead, the girls panic. Ye-ji decides to protect Min-so by taking the blame herself and removes the dashcam memory card. She tells Min-so not to tell anyone and confesses to her father, Je-hoo, that she accidentally hit someone. Terrified, Je-hoo rushes to the scene to cover up the crime for his daughter. Meanwhile, Min-so confesses everything to her mother, Soo-jung, who also rushes to the scene to protect her daughter. Neither parent realizes that both girls were in the car together.

At the crash site, the lawyer finds the unconscious P.I., reclaims his phone, but accidentally chokes the injured P.I. to death during a struggle. Realizing he just committed murder, the lawyer flees after drowning his own car in a nearby river to destroy evidence.

When Je-hoo arrives, he finds the P.I.'s body (assuming his daughter killed him) and decides to hide it. Meanwhile, Kyung-hee tracks Je-hoo's location via the GPS tracker in his wallet. Expecting to catch him cheating, she is horrified to find him dragging a corpse. Je-hoo breaks down and tells her that their daughter Ye-ji accidentally killed a man. To protect Ye-ji, Kyung-hee agrees to help, and they load the body into their car to bury it in the countryside cellar.

Watching from afar, Soo-jung secretly films Je-hoo and Kyung-hee loading the body, planning to use the footage as leverage to frame Ye-ji if necessary to save her own daughter, Min-so.

Later, Soo-jung approaches the terrified girls and offers to "handle everything." She takes the dashcam memory card from Ye-ji and immediately destroys it, eliminating proof of Min-so's involvement so she can place the entire blame on Ye-ji using the video of Je-hoo and Kyung-hee moving the body.

Je-hoo and Kyung-hee bury the P.I.'s body inside the underground cellar and meticulously clean the crime scene. Meanwhile, the lawyer realizes he accidentally took the P.I.'s phone instead of his own during the struggle, leaving his own phone with all his incriminating secrets missing.

The next morning, Je-hoo receives a blackmail text demanding 500 million won ($400,000) by 5:00 PM, or else "the footage will be released online." Assuming it is footage of them burying the body, Je-hoo and Kyung-hee desperately scrape together cash from savings, company funds, and loans. Short on cash, Je-hoo even borrows 100 million won from Soo-jung without telling Kyung-hee, pretending it came from his boss. He also dumps his car at a scrapyard and files a false police report claiming it was stolen.

Meanwhile, Min-so feels immense guilt and visits the crash site. There, she meets Na-doo—the violent, intimidating twin brother of the dead P.I. Na-doo is searching for his missing brother. Ye-ji arrives just in time to pull Min-so away before Na-doo realizes who they are.

At 5:00 PM, Kyung-hee delivers the cash to the specified locker, using a location tracker inside the money bag to follow the blackmailer. She tracks the bag to a house and confronts the blackmailer—only to find it is the clinic manager. The manager apologizes, explaining that she didn't film the murder, but rather recorded Je-hoo and Soo-jung's secret affair at the clinic.

Kyung-hee is completely devastated. She realizes her husband wasn't just covering up a crime; he was cheating on her with their neighbor. When Je-hoo arrives, Kyung-hee angrily forces Soo-jung to come inside and plays the video on the big screen in front of both of them. Exposed, Je-hoo begs for forgiveness, but Kyung-hee slaps him, declaring that from now on, they are strictly business partners.

When the police show up at the house, everyone panics thinking the crash was discovered, but it turns out Soo-jung's ex-husband called the police reporting Min-so missing. During the chaos, Je-hoo checks Ye-ji's phone and discovers that Ye-ji has saved Min-so's number as "My Love," matching couple rings they both wear. Je-hoo realizes that Ye-ji went as far as covering up a hit-and-run because she is deeply in love with Min-so.

Meanwhile, drunk teenagers find Je-hoo's abandoned car at the scrapyard, get caught driving it by the police, and the vehicle is returned to Je-hoo. The lawyer, searching for cars with front-end damage to locate his missing phone, identifies Je-hoo's car at a repair shop and realizes Je-hoo is connected to the incident.

Tensions mount. Kyung-hee collapses from severe stress while working on a project with Bu-seon (Soo-jung’s ex-husband). Bu-seon takes care of her, and Kyung-hee finds herself developing feelings for his kindness.

Meanwhile, the lawyer befriended Je-hoo at the gym under a fake identity. He slips a sleeping pill into Je-hoo's drink one evening and searches Je-hoo's house for his lost phone. He finds the phone hidden inside a salt container in the refrigerator, but while retrieving it, he drops the memory card on the floor. Ye-ji finds the memory card, plays it, and accidentally watches the video of her father's affair with Soo-jung. At the same time, Min-so discovers her mother's affair, leaving both girls deeply traumatized by their parents' hypocrisy.

Na-doo (the twin brother) tracks down Je-hoo using credit card transactions left by his missing brother. He discovers that his brother was investigating the lawyer and realizes his brother was murdered.

When the lawyer returns to Je-hoo's house to retrieve the dropped memory card, he is cornered by Je-hoo, Kyung-hee, Soo-jung, and Bu-seon. A chaotic confrontation breaks out as the lawyer threatens to expose everyone's secrets—including the hit-and-run, the affair, and the buried body. During the struggle, the lawyer slips, hits his head hard against a table, suffers a severe brain hemorrhage, and dies on the spot.

Hearing about the commotion, Ye-ji and Min-so flee to Kyung-hee's countryside villa. However, Na-doo tracks them there. Overhearing the girls discussing the accident, Na-doo realizes that these two girls were involved in his twin brother's death and takes them hostage in the garage.

Ye-ji manages to call her mother, crying that they are being held hostage at the countryside house. Kyung-hee, Soo-jung, Je-hoo, and Bu-seon set aside their differences and race to the villa to save their daughters.

At the garage, Na-doo demands to know who killed his brother. To protect Ye-ji, Kyung-hee claims Min-so was the driver, while Soo-jung claims Ye-ji was the driver. When Na-doo threatens to kill them, Kyung-hee offers to show him where his brother's body is buried to buy time.

When Je-hoo and Bu-seon arrive, a desperate brawl breaks out against Na-doo. Working together, the four adults and two girls overpower Na-doo, and Bu-seon strikes the final fatal blow to protect the children.

Realizing they have now accumulated three dead bodies (the P.I., the lawyer, and Na-doo), the two families panic. Out of options, they bury all three corpses inside the underground cellar at the countryside house, burn all evidence, and dump Na-doo's car at the scrapyard.

A month later, the police locate the lawyer's submerged car in the river and launch a murder investigation. They question Kyung-hee and Je-hoo, but Kyung-hee provides a plausible story: she hired Na-doo as a private investigator to track her cheating husband, and Na-doo disappeared after a fight with a known criminal associate. The police conclude that the shady criminal killed both Na-doo and the lawyer, completely exonerating the two families from suspicion.

In the aftermath, Soo-jung keeps her copy of the body-burial video, and Kyung-hee keeps a copy of the final brawl video, ensuring a cold stalemate where neither woman can ever betray the other.

Due to the public scandal of the affair leaking, Je-hoo and Kyung-hee shut down their main YouTube channel, and Kyung-hee's former assistant takes over her company. However, Je-hoo and Kyung-hee decide not to divorce, choosing to stay together to rebuild their family. Soo-jung's clinic goes bankrupt due to the scandal, while Bu-seon's new clinic thrives.

In the final scene, a news report broadcasts that the missing twin brothers and the lawyer were victims of an organized criminal feud. Watching the news together, Min-so and Ye-ji finally realize that they are officially cleared of all charges, finding peace at last.

Cast and Characters

Kim Hye-sooas Kyung-hee

Cho Yeo-jeongas Su-jeong

Kim Ji-hoonas Jae-hong

Kim Jae-chulas Bo-seong

Do Yeong-seoas Joo Min-Seo

Jeon Si-hyunas Lim Ye-Ji