As Episode 4 of "Surely Tomorrow" unfolds, Kyeong-do escorts Ji-woo to the hospital, where doctors conduct thorough examinations. Se-young returns home to tend to their child, while Kyeong-do stays by Ji-woo's side throughout her stay. Upon her discharge, Kyeong-do escorts her home and inquires about the sleeping pills she consumed in conjunction with alcohol.
Ji-woo explains that she took them after a meeting with her mother, growing increasingly irritated by Kyeong-do's persistent concern. She retreats inside, but Kyeong-do follows closely behind. He pours all her alcohol down the sink, reminding her of the public scandals that have arisen from her past drinking incidents.
Frustrated by his constant oversight, Ji-woo requests he leave. Kyeong-do's temper flares as he tells her she's ruining her life, but he calms down as he confesses his own struggles with similar temptations, urging her to stop before her dependence spirals into addiction. Despite her repeated requests for him to leave, he insists she partake in some porridge after having her stomach pumped.
The narrative shifts to 2007, when Ji-woo and Kyeong-do were in a romantic relationship. Kyeong-do presents her with an orange dress, and she praises the effort he put into earning the money for it. In return, Ji-woo buys him an orange T-shirt, which he later refuses to discard. Kyeong-do hesitates to accept the expensive gift, fearing it would make their relationship seem transactional, but Ji-woo insists, and he eventually gives in.
That night, his mother informs him that she earned 300,000 won from laundry that month. He realizes the T-shirt costs more than her family's monthly income and becomes acutely aware of the gap between their lifestyles.
As the drama club prepares for their play, Ji-woo invites Kyeong-do to dinner. She craves tteokbokki, but he insists on pork cutlets. Confused by his behavior, Ji-woo presses him until he admits he's struggling to accept that she is significantly wealthier than he is. Ji-woo is hurt, but Kyeong-do explains they are too different for her to understand his position. She eventually breaks down, grasping his feelings for the first time.
Their relationship abruptly ends, and Ji-woo retires to her room. Over the next few days, she refuses to eat or leave her room, ignoring Kyeong-do's calls. One night, after she collapses, her mother takes her to the hospital. There, Ji-woo agrees to return to the USA. She leaves Kyeong-do a final message, asking him to find happiness while she searches for her own. His depression deepens after her departure.
In the present, Kyeong-do persistently sends Ji-woo articles detailing the detrimental effects of alcohol on both mental and physical health. Annoyed by the constant reminders, Ji-woo confronts him at his building, forcing him to skip work and takes him to a nearby park. As they argue over the articles, their tempers fray, leading them to walk barefoot on a stony path to cool off. Ji-woo attempts to wash her feet but is unable to remove all the dirt, so Kyeong-do takes over, washing and drying them before driving her home as she naps.
Later, Ji-woo meets with Ji-yeon and reveals her plans to still travel to the UK. She shares with her sister the argument she had with their mother about her biological father, insisting that she is not the rightful heir to Jarim Apparel and desires no part of the inheritance. Meanwhile, Jarim's Executive Director Choi meets with Min-woo, who discusses Ji-yeon's Alzheimer's and urges her to sell her shares before the company collapses. ED Choi inquires about Ji-woo as a potential replacement, but Min-woo expresses her disinterest and makes an offer that ED Choi cannot refuse. That night, Min-woo gives Secretary Yoo drugs and instructs her to administer them regularly to Ji-yeon.
Concurrently, Nam-sook finds Kyeong-do napping outside their house, reminding her of his heavy drinking days. She checks on him and is relieved to see he is sober. They engage in a conversation, with Kyeong-do asking her to pray for a friend with an alcohol problem. While concerned, Nam-sook jokes to lighten the mood. Meanwhile, Ji-yeon visits Hyun-kyung at the hospital and confronts her mother about treating Ji-woo with indifference rather than love. She lashes out and leaves before hearing a response. Da-hye sends Min-woo a note from prison inquiring about the drugs he is seeking for his wife's treatment.
Elsewhere, Kyeong-do meets his general manager, who offers him a one-year transfer to Chicago and commends his work at Dong-woon Daily. Over lunch, his friends celebrate the opportunity and inquire about subletting his apartment. Jeong-min admits he is considering staying for Ji-woo's sake but calls the relationship self-sabotaging and urges Kyeong-do to stop worrying about her. He becomes emotional as he recalls nearly ending his life because of addiction. The episode flashes back to 2017, when Kyeong-do was drinking heavily throughout the day. His friends tried to help, and Manager Han-kyung grew concerned as he drank on the job. Nam-sook often found him passed out on the street and took him home.
One fateful night, his unconscious hand pushed her away, leaving her injured. Later, she found him in the bathroom with a bleeding palm and called upon Jeong-min to assist in taking him to the hospital. When Kyeong-do learned of Nam-sook's fracture, he fell apart, apologized, and decided to embark on a journey of rehabilitation.
Flashing back to the present, Kyeong-do thanks Jeong-min for guiding him back then. He cooks beef for Ji-woo, watching her eat with a struggle to hide his emotions. After cleaning up, he secretly slips her last bottle of alcohol into his bag. Later, Ji-woo texts him her coordinates. He rushes from work to meet her at the university garden.
That evening, Ji-woo tells him that she cannot continue living in Korea and admits that being around him is challenging. She confesses her fear of developing feelings and says that if he stops her again, it will mean he cares for her more than just an old friend.
That night, Kyeong-do mixes an energy drink with sparkling water to steady himself and reflects on their conversation before making a sudden decision. Meanwhile, Jin-eon arrives at Ji-woo's house, asking for reconciliation. She appears frightened and refuses his offer. When he threatens her, Kyeong-do arrives with his luggage and declares that he is there to win Ji-woo over. The episode ends with Kyeong-do once again attempting to throw away the orange T-shirt, only to retrieve it. His parents urge him to discard it, but he refuses, calling it his security blanket—a symbol of his unwavering commitment to his feelings for Ji-woo.
