Mu-jin confesses his feelings for Gyu-rim, but Gyu-rim turns him down, telling him that life is too hard for her to date anyone. Gyu-rim suddenly gets worried that she might have to live the rest of her life taking care of her siblings, so she tells them she's getting married out of the blue. Meanwhile, Yun-hee gets into a car accident, and it turns out the other driver is her ex-husband.

As Mu-jin and Gyu-rim settle into a blossoming romance, Mu-jin decides he can no longer hide the truth and finally reveals the secret he has kept from her. Reeling from the unexpected revelation and Hong Ok-seon's fierce opposition, the couple vows not to let go of each other, only for an unforeseen crisis to threaten everything they have chosen to protect.

Mu-jin is severely injured while working as a day labourer at a construction site. Meanwhile, his older sister, Yoon-jin, confronts Gyu-rim and urges her to end her relationship with Mu-jin. At the same time, Gyu-rim's family is evicted from their home. Eight years later, Gyu-rim lives with her young son, Gyeol. However, she is summoned to the police station, where she comes face to face with someone she never expected to see again.

Eight years after losing Gyu-rim, Mu-jin finds her beside her son Han Gyeol and Heung-sik, who seems to be her husband. He tries to accept the life she appears to have built without him, but his feelings refuse to disappear. Meanwhile, Gyu-yeong hides her family as she prepares for a meeting before marriage, setting the stage for another painful collision.

Mu-jin suspects Gyeol might be his son, but Gyu-rim quickly brushes off his suspicions. Gyeol once again asks Mu-jin to meet, and when they sit down together, Gyeol surprises Mu-jin with an unexpected question. Meanwhile, Yun-hee learns that Gyu-yeong had asked Hun-tae for help with her wedding and decides to meet with her. However, Gyu-yeong is disappointed when Yun-hee's attitude is completely different from what she had expected.

Pressed by young Gyeol about his lingering affection, Mu-jin insists he holds no desire for someone already married. Elsewhere, Gyu-rim fiercely defends her secret against Jeong-wu, adamant that her son shares no connection with Mu-jin. Still, keeping the past deeply buried proves impossible.

After learning that Heung-sik was injured while trying to save Gyeol, Gyu-rim gradually grows attached to Heung-sik. Meanwhile, Gyu-yeong, fired from the hospital, returns to Gyu-rim's home, showing signs of causing trouble once again. Elsewhere, Ok-seon discovers Gyeol's existence and begins looking into his background in secret, even planning to take him away from Gyu-rim and raise him herself.

Mu-jin decides to start a new relationship with Seo-hyeon, but he can't shake the heaviness in his heart. Meanwhile, after learning about everything from Gyu-yeong's formal family meeting to the excessive wedding gifts being demanded, Gyu-rim resolves to stop the marriage.

After getting drunk, Gyu-rim runs into Mu-jin on her way home, but the next morning, she suffers from a terrible hangover and has no memory of meeting him. Still, she can't shake the feeling that something is missing and searches for what she may have lost, left with an uneasy feeling. Meanwhile, Yun-hee confronts Mu-jin and harshly declares that she will never approve of his relationship with her daughter.