On a yacht in the ocean, Dal-go appears in a diving suit. Kwang-ho pats Dal-go’s shoulders and says, “All you need to do is fetch it.” Dal-go dives into the ocean and Hee-jung looks at the yacht through a telescope from the distance. Then a Coast Guard boat races towards the yacht, causing Kwang-ho and the others to panic as they realize that Dal-go is still in the water. Dal-go retrieves the box and looks towards the yacht. He senses that something is wrong when he sees the yacht moving further away. He abandons the box, and comes up to the surface. Dal-go tells Jang-sik that he abandoned the box, but Jang-sik tells Dal-go to stop lying and bring the box with him. Dal-go begs Jang-sik to let him go if he can run away. Dal-go runs for his life, covered with blood before he finally collapses. He wakes up in a hospital and smiles as he realizes that Yoo-nah is taking care of him. Two months later, Dal-go is living a good and quiet life delivering ice to fish markets. Dal-go follows Yoo-nah onto the bus she takes to commute to work, and sits right next to her while she is sleeping. He wants to wipe off the milk off from around her mouth, but he can’t.
Dal-go goes to the boarding house looking for his mother, Yeon-ji. When he finds his mother, he asks her to stay there for a few days since he is going to Seoul for business. Jang-sik tells Dal-go to bring back the lost box or that he will hold his mother as a hostage until he gets it. Dal-go is upset but he can not refuse. Yoo-nah is kicked out of the hospital and does not return home, when Hye-young finds her. Yoo-nah goes back to Dal-go’s neighborhood looking for the house she slept in before. It takes a few days for Dal-go to find the lost box in the ocean. Jang-sik demands the box, but Dal-go tells him to bring his mother back home first. Dal-go asks Jang-sik to promise him that this will be the last time he has to work for him. At that moment, Kwang-ho shows up in the office, just after being released from jail. Feeling awkward, Dal-go and Jang-sik drop what they were holding and give Kwang-ho a hug. Yoo-nah is staying at a boarding house, and one day when she finds Hye-young and Jin-gyu in her room she is surprised and bursts into tears in Hye-young’s arms.
Dal-go is caught by the gang at the airport while trying to leave with Yeon-ji. Yoo-nah spots the organization chart of the Sharksfin Gang when she rummages through the personal belongings of her late brother, Detective Kim. Dal-go is beaten by the gang but he is happy to see Kwang-ho stand up for him. Kwang-ho asks Dal-go to go to jail for him and promises to get him out of the jail. Dal-go yells Yoo-nah’s name loudly in front of her house, but is surprised when Yoo-nah comes out of the house. When Yoo-nah sees his scar, she remembers him. Yoo-nah asks why he came to her. Dal-go stumbles over his words but manages to express his feelings for her. Dal-go blows soap bubbles towards Yoo-nah’s room and Yoo-nah watches the bubbles with her head sticking out of the window. Yoo-nah goes to Hee-jung and asks to meet the man who surrendered himself.
Dal-go, who got out of jail, runs as hard as he can with Jang-sik behind him. Yoo-nah, who is waiting for Eun-tak at the hospital director’s office, grows uneasy as she looks around the room. After a conversation with Eun-tak, Yoo-nah leaves the office and bumps into Mary on her way out of the hospital. Yoo-nah asks Mary whether the place is really a hospital. Hee-jung gets confused when she sees Yoo-nah, who looks exceptionally pretty, and Hee-jung calls Eun-tak up and explains her symptoms.
When Dal-go comes to Seoul, he goes to Hee-jung and presses her about his mother’s whereabouts. Hee-jung takes Dal-go to his home. When Dal-go is about to enter the house, he sees Yoo-nah passing by the gate. Dal-go is happy as he realizes that he will live in the same house with Yoo-nah. Dal-go saves Yoo-nah, who is in trouble, and runs as hard as he can, holding Yoo-nah’s hand. On the way home, Yoo-nah feels uneasy because Dal-go is following her. The following day, Dal-go visits Eun-tak’s hospital, which Hee-jung had told him about.
Dal-go and Yoo-nah remain in the director’s office which Eun-tak and Mary leave. Yoo-nah looks suspiciously at Dal-go’s gown. Then, President Ko and the gang appear at the hospital and Mary asks them to wait a little longer as she has hired two more doctors. Dal-go and Yoo-nah appear in doctor’s gowns before President Ko, who says he will sell the building. Dal-go and Yoo-nah put on an outstanding performance and escape the situation. Bong-su and Dal-go are surprised at each other and Bong-su introduces Dal-go to President Ko as his college alumnus.
On the way to home, Dal-go and Yoo-nah talk as if they are fighting. Dal-go explains his troubles to Yoo-nah, but Yoo-nah tells him to look for another job. The next day Dal-go helps Yoo-nah clean up the hospital. Hee-jung asks Dal-go if Kwang-ho is really the suspect, and tells him that they might reopen the investigation. Hye-young breaks her water and goes to Bong hospital for delivery. Eun-tak follows Mary into the delivery room.
Yoo-nah sees Dal-go getting mad at his mother, Yeon-ji, and tells him that he shouldn’t do that. Dal-go comes back into the house to apologize to his mother for his rudeness, then leaves. Yeon-ji is surprised to hear his apology because it is the first time she has heard him apologize. She askes Yoo-nah what happend. Dal-go chases down a bus and gets one foot on the bus waiting for Yoo-nah. Dal-go drinks the milk that Yoo-nah offers and asks her to buy him breakfast. Eun-tak advises Hee-jung to go to a movie theater when Hee-jung asks what to do if a girl looks pretty. Dal-go and Yoo-nah have breakfast together. Yoo-nah is happy to hear that the facility will accommodate a diabetes class. Dal-go receives the movie ticket that Hee-jung sent to Yoo-nah and opens the envelope after some hesitation. Dal-go tells Yoo-nah that Hee-jung sent movie tickets, but Yoo-nah is not listening to him. The next day, Hee-jung asks Dal-go why he didn’t give the tickets to Yoo-nah and asks him if he likes her.
Dal-go goes to Bong-soo’s goshiwon room and gets angry at him because his gang members have been bothering Yoo-nah. Having no place to go, Dal-go goes back home and Yoo-nah glares at him. Feeling uncomfortable he comes back out and goes to Hee-jung’s house. Dal-go secretly gets onto the same bus that Yoo-nah takes to the hospital and watches her as she goes inside. Eun-tak offers Dal-go a farewell drink telling him that he heard that Dal-go has quit working at the hospital. Mary hears from the gang that Dal-go knows the reason why he hit them. Dal-go prepares a resume to get a new job but finds that it isn’t that easy. Dal-go, who has been lingering around the Bong Hospital, goes into the hospital using Eun-tak as an excuse and Yoo-nah leaves. He follows Yoo-nah and asks her whether he could stay if he promises never to use his fists in any way. Hee-jung hurts his leg while telling Yoo-nah to get into the car because he has something to say to her and she treats his wound. Yoo-nah finds out that Dal-go saved her from getting raped. Eun-tak suddenly faints while drinking with Dal-go and Dal-go runs to the hospital carrying him on his back. Seeing this, Yoo-nah and Mary run out surprised.
Dal-go and Yoo-nah sit on the wooden bench in their yard and talk. Yoo-nah laughs out loud and Dal-go tells her not to laugh like that in front of others and as he notices that Yoo-nah is thirsty he happily runs to gets some milk for her. Dal-go stops in front of the house and thinks about his feelings toward her, but is surprised when Yoo-nah calls for her. As Yoo-nah sees Dal-go draw back from wiping off the milk from her mouth she takes his hand and wipes it off. Then she takes his hand to go into the house but, surprised by this, he pulls his hand away.
Eun-tak, who has been discharged from the hospital sells his little room and decides to live in the hospital. Dal-go tries to soothe Yoo-nah, who has gotten angry because he told her that he can not understand her words. The next day, Yoo-nah bends down to put on her shoes and is surprised to see a carton of milk. She follows the milk cartons to the front door where Dal-go is standing with a big smile on his face. Dal-go doesn’t like the idea that his birthday party is being held at Hee-jung’s house but he follows Yoo-nah to the house anyways. On the way home after the party, Dal-go gets angry at Yoo-nah for washing the dishes at Hee-jung’s house and Yoo-nah suddenly hugs him.
Dal-go goes the to Officer Kim’s grave in the cemetery and stands in front of it asking him to please let him and Yoo-nah be together. Yoo-nah takes care of a patient forgetting that she, too, has a high fever. Dal-go worries about how he’s going to tell Yoo-nah about everything, and when he sees some students, he decides to ask them for some help. Hee-jung asks Yoo-nah for some of her time and the students follow her and slide the letter Dal-go gave them into her purse. Hee-jung starts to sing a song for Yoo-nah but when she sees Dal-go’s letter and piece of clothing she gets up and leaves.
Yoo-nah follows the sound coming from Dal-go’s watch to find him. Dal-go tells her that there is a thing that he hasn’t told her yet but someday he is going to ask her for her forgiveness. She asks him what his dream is and he tells her that his dream is her and she runs and hugs him. Dal-go decides to study for the school qualification exams and learns English from Yoo-nah. Hee-jung asks Dal-go what would happen if he told Yoo-nah that he had a part in the death of her brother and Dal-go tells him that he is going to tell Yoo-nah the truth.
Yoo-nah goes to Hee-jung to ask him why Dal-go is in the lineage graph but he tells her that she is going to hear the reason from Dal-go soon. Dal-go calls Hee-jung and tells her to come quickly because Bong-soo is being threatened by Jang-sik, so Hee-jung quickly leaves. Yoo-nah, not knowing what is going on, walks the streets out of her mind, and collapses from not having the strength to walk anymore. Even when she gets home she just sits with a blank look on her face. Dal-go tries to tell Yoo-nah the truth but she tells him not to say another word until she is ready to hear it.
Ko finds out the Bong-soo is a quack and insists that he is going to sue doctor Bong. Yoo-nah and Dal-go go to Ko’s house and tell him the details of why they lied and go out looking for Bong-soo. Yoo-nah hears the truth from Dal-go and drinks in pain, and Dal-go puts her on his back and carries her home. Dal-go asks Hee-jung to help so that Yoo-nah’s doctor’s license does not get canceled and Hee-jung tells him that he’ll help only if Dal-go promises to leave Yoo-nah.
Yoo-nah follows Dal-go through the front door and as they get in she holds out the watch and asks him what it means but he just ignores her and leaves. Yoo-nah becomes numb, and with earphones in her ears just lays down on the spot as tears run down her face. Hye-young tells Yoo-nah to come back to work at the hospital because all the problems have been worked out. Dal-go meets Kwang-ho’s lawyer, Jin-shik, and is dumbfounded at his words, telling him to prove that he did not kill Officer Kim. Hee-jung tells Dal-go to just come to the hospital and work, and at that he asks Hee-jung if Yoo-nah will go to him if he leaves the hospital. Dal-go and Yoo-nah find that one of the homeless people is in need of surgery as soon as possible and go together to get a consent form. On the way they get into an accident and Dal-go frantically looks to see if she is o.k. Yoo-nah just stares at Dal-go and he hastily turns around. Yoo-nah gets water splashed all over her and so she borrows some clothes from a farmhouse while she dries her clothes, and Dal-go calls her name, looking for her. Yoo-nah feels sorry to keep Dal-go waiting for her and Dal-go leaves Yoo-nah alone and calls Hee-jung.
Dal-go stands in front of a music store staring at a cello, once again feeling that there is nothing he can do for Yoo-nah. Yoo-nah tells Dal-go that she might have to go as a witness to court and asks him if he came to see her the night Officer Kim died, but he gets angry at her and tells not to do that. Yoo-nah tells him that he is so sincere to her right now that even her brother’s death means nothing to her. Dal-go follows Yoo-nah and tells her that he is very thankful for trusting him and forgiving him but that he doesn’t have the strength to live life being a man fit for her. While crossing the street very dangerously Yoo-nah tells him that if they really need to be fit for each other than she will become a hooligan. Hearing this, Dal-go runs and hugs her.
Jin-gyu goes to the bank with Jang-sik and asks him if they can make a contract before they withdraw the money at 3:00 p.m. Dal-go tells Hee-jung the details of the night Officer Kim died and apologizes for not being able to keep the promise they made. After the meeting with Hee-jung, Dal-go and Yoo-nah go to a quiet park and take a nap. Soon-ae, who has been waiting for Yoo-nah in front of the house, tells her that she can not get in contact with Jin-gyu, and Dal-go tells Yoo-nah to go to Hee-jung and tell him that Jin-gyu is with Jang-sik, then goes out looking for Jin-gyu.