Moo-hyuk tries to strike a deal with Eun-chae. He will donate his heart to Yoon after he dies and in return, she has to spend his remaining days with him. Eun-chae thinks he is joking about death again and gets angry. Out of spite, she agrees and asks Moo-hyuk to keep his promise to die so that Yoon can live.
Meanwhile Eun-chae's father, who is Deul-hee's driver, finds out about Moo-hyuk's condition and tells Deul-hee. Deul-hee buys clothes, food and many other stuff for Moo-hyuk and his family. Moo-hyuk is touched and almost forgives her. However, he sees the health supplements which is good for the heart that she bought for him and realizes her true intention - she is literally trying to "buy" his heart.
An angry Moo-hyuk goes to her house and shouts outside her gates,
"I'm your son too, just like Yoon! You gave birth to me! You brought me to this world! I'm your son too..."
Eun-chae's father, who knew all along that Moo-hyuk is Deul-hee's son, is the only person who heard his shouting. He berates Deul-hee the next day,
"Is only your son's life valuable? Moo-hyuk's life is just as valuable to his parents! At least Yoon has hope to survive but Moo-hyuk has nothing. He can only wait for death hopelessly. At least Yoon has a mum who is trying to save him. Moo-hyuk only has a retarded sister who doesn't even know what death is and a young nephew. Let him live the rest of his life in peace, please!"
Eun-chae overhears and is shocked. She recalls the cruel things she said to Moo-hyuk and breaks down. She goes to Moo-hyuk but his condition worsens and he chases her away.
Moo-hyuk meets Deul-hee to thank her for her gifts, and informs her that he has registered to have his heart donated to Yoon when he dies. Deul-hee is guilt-stricken and tries to reject the offer. Moo-hyuk smiles when he sees her crying.
Yoon goes to Moo-hyuk's house to ask him what his agenda is. Moo-hyuk reveals that they are half-brothers, and he plans to take revenge on Deul-hee by giving her a call before he dies and telling her,
"Mother, I am the son you abandoned. I am dying for your precious son. For your jewel-like son to live, your trash-like son is dying."
Moo-hyuk wants to find a place to die alone quietly. However, Eun-chae finds him and they spend some happy time together. Moo-hyuk is determined to break up with Eun-chae and in another classic scene of the drama, before they part, she repeatedly cries, "Saranghae!" to him outside the subway station.
When Moo-hyuk gets home, he finds Yoon waiting for him. Yoon tells him a shocking truth - he is actually an adopted son. Deul-hee adopted him as a substitute for the son she abandoned out of circumstances and could not forget. A shocked Moo-hyuk learns the whole story from Eun-chae's father - Deul-hee was a famous actress and she had an extra-marital affair with a movie director. She gave birth to a pair of twins but her mother felt that their existence would ruin her future, so she got Eun-chae's father to abandon the babies. They lied to the devastated Deul-hee that she gave birth to a stillborn son.
After knowing the truth, Moo-hyuk is aggrieved that he had spent the remaining days of his life hating his mother. He goes to look for her and asks her to cook something for him. She exasperatedly cooks him a bowl of noodles and he secretly cries while he eats it. He decides not to tell her that he is her son, to spare her the pain of losing him again. He kneels outside her house to thank her for giving birth to him and promises that if there is a next life, he will be a good son to her.
Moo-hyuk kills himself in a motorcycle accident and his heart saves Yoon's life. Deul-hee, who feels a deep affinity to his sister (her daughter, although she doesn't know), takes care of her and her son. Eun-chae loves Moo-hyuk so much that a year later, she commits suicide in front of his grave.
