Buried Hearts episode 5 was released on March 6, 2025. In the previous episode, Eun-nam and Hui-cheol crossed paths with Dong-ju, portrayed by Park Hyung-sik, at the boutique store. Eun-nam approached Dong-ju, but he did not recognize her.
In episode 5 of Buried Hearts, Hui-cheol was baffled when Dong-ju mentioned that he had lost his memory. He threw a jab at Dong-ju but fell after Dong-ju dodged. Eun-nam handed her phone to Dong-ju before leaving with Hui-cheol. Later, Hui-cheol informed Gu-ho that Dong-ju had been at Gangnam Q Salon, the boutique.
Buried Hearts episode 5: Did Gu-ho find Dong-ju?
In episode 5, Sang-jeon's wife fretted over his health, while Gu-ho updated Sang-jeon before heading to Gangnam Q. Meanwhile, the mysterious man from episode 4 of Buried Hearts made a return. He and his henchmen prepared a torture room. Gu-ho, disguised as a delivery person, cordoned off the area near Gangnam Q. Just as he was about to attack Dong-ju, the boutique's manager approached Dong-ju and invited him for a private chat.
The scene in Buried Hearts episode 5 then shifted to a medical conference room, where two doctors and Chairman Cha were discussing his brain health. Chairman Cha had ordered Dr. Kang Il-hyeon to report directly to him for a verdict on his health checkups. The other doctor was Do-su, the chairman's second son-in-law.

Gu-ho just missed Dong-ju and headed out to find him. It was revealed that Dong-ju was at the same restaurant as Chairman Cha and Do-su, who were having a meal to ease the chairman's worries. The chairman fretted over forgetting Hui-cheol's birthday, but Do-su reassured him. Dong-ju got up and left, but the cashier noticed him. He walked up to the chairman to inquire, and the latter rushed out to seek Dong-ju.
Later, Eun-nam called Dong-ju from Hui-cheol's phone, telling him to meet her that night at the chairman's house. Dong-ju recalled his conversation with the boutique's manager and Won-bae. Meanwhile, Gu-ho and his team were watching him from afar and planned to attack him. Just then, the chairman approached Dong-ju, and Dong-ju prepared to attack.
Buried Hearts episode 5: Does Dong-ju recollect his memories?

Dong-ju did not remember the chairman, prompting Do-su to call for a car to take them all home. However, Dong-ju spotted a taxi and ran away. Gu-ho followed the taxi but lost him. He later updated Sang-jeon on Dong-ju's condition.
Next, in Buried Hearts, Eun-nam confronted her mother about the phone and her marriage. The scene shifted to a flashback where Eun-nam engaged in self-harm to make her mother admit that she knew Il-do had killed her father.
Eun-nam then went to Il-do to take her phone and informed him that Dong-ju was back. Meanwhile, Hui-cheol made up a lie about his head injury. Just then, the chairman arrived with Do-su, announcing that they had met for a Daesan Hospital Management meeting. The chairman lashed out at Hui-cheol for crying about his personal affairs. However, when a staff member reminded him about Hui-cheol's birthday, he brushed it off as a joke.
Eun-nam recalled her past interaction with Dong-ju. Meanwhile, Il-do spoke with Sang-jeon about Dong-ju. Sang-jeon warned Il-do to be careful as they suspected Dong-ju could be faking his memory loss. Il-do grew worried. Dong-ju recollected some memories about Il-do as he searched for Il-do on the internet. Dong-ju and Eun-nam talked on the call as he headed to the chairman's house. Il-do was shocked to see Dong-ju at the house.
Buried Hearts episode 5: Does Secretary Gong know Seong-hyeon?
Next, in Buried Hearts episode 5, Dong-ju arrived at the dinner party, shocking everyone. He introduced himself as Seong-hyeon. When asked about the name change, his answer shocked Secretary Gong. Meanwhile, Secretary Gong and Ja-ok were transferring the cake to the table, but Secretary Gong dropped it. The chairman then invited Il-do, Do-su, and Dong-ju to his office. Dong-ju talked to Il-do about saving him from the sea, and Il-do played along.
Meanwhile, Do-su talked to Dong-ju about his memory loss to determine its extent. The chairman ordered Do-su to get Dong-ju hospitalized and tested. Il-do later updated Sang-jeon on the matter.

The scene in Buried Hearts episode 5 then shifted to Secretary Gong. Deok-hui visited her and asked if hearing the name 'Seong-hyeon' had caught her off guard. Secretary Gong shrugged the matter off. Deok-hui reaffirmed that the child was already dead.
Later, Dong-ju was asleep in his hospital bed when someone came into his room. Elsewhere, Chairman Cha waited for Doctor Kang to ask about Dong-ju's test results. It was then revealed that the mysterious man in Dong-ju's hospital bed was Sang-jeon. Dong-ju woke up to find Sang-jeon, and he was scared. Soon after, the chairman and Doctor Kang arrived, and she noticed Dong-ju's discomfort. She asked them to leave, and Sang-jeon warned her that Dong-ju could be faking his condition.
Doctor Kang then spoke to Dong-ju about the next plan of action for his test. She asked if he had recalled any memories overnight. She also told him that he would have to undergo a psychiatric evaluation. It was later revealed that Sang-jeon had planted a listening bug under Dong-ju's bed.
Sister Agnes helps Eun-nam to retrieve Dong-ju's memories in Buried Hearts episode 5
Later in Buried Hearts episode 5, Eun-nam visited her former home with Dong-ju. She found the engagement ring, took a photo with it, and left. She then left to visit Sister Agnes. Sister Agnes told Eun-nam that Dong-ju had lost his memory before when he was very young and that he had only remembered his name.
Upon hearing the name Seong-hyeon, Sister Agnes was shocked too and told Eun-nam to wait for her. Eun-nam then informed the chairman, who told her to bring Sister Agnes in hopes of jogging Dong-ju's memory. Meanwhile, Il-do asked the chairman how he would access the safe if Dong-ju never regained his memories. The chairman was concerned as the safe could not be easily opened. Just then, Il-do received a message to meet up urgently.
Doctor Kang visited Dong-ju and found him working out shirtless. She noticed the bullet wounds on his body. She handed him a questionnaire to fill out before the test and asked him about the wounds. A man came to take him for the brainwave test, but he was not a medical staff member. He injected Dong-ju with a drug to render him unconscious and took him away.
The chairman informed Doctor Kang about Sister Agnes. As he attempted to open the security room, he recalled a conversation with Dong-ju about Ju Seon-u. Around the same time, Doctor Kang noticed that Dong-ju had been kidnapped. Eun-nam and Sister Agnes arrived at the hospital just as Dong-ju was being taken away by Gu-ho.
The mysterious man from earlier began his torture of Dong-ju to retrieve the passwords. The episode concluded with Dong-ju losing consciousness in the pool of water.
Buried Hearts episode 6 is expected to air on March 8, 2025.