Episode 3 of "Our Unwritten Seoul" kicks off with Ho-su's startling recognition of Mi-ji, despite her clever dissuasion that he's merely mistaking her for someone else. A cascade of vivid flashbacks then unfolds, painting a picture of their once-tight bond during high school, which fractured under the shadow of suspicion. Mi-ji had grown to believe that Ho-su was dating her rival, Mi-rae. On the pivotal day of her crucial race, her heart shattered as she witnessed the pair in a tender embrace from afar. Distracted and disheartened, she stumbled and suffered a devastating ankle injury, her athletic aspirations shattering along with it. Abandoned by all she once held dear, Mi-ji clung to a desperate hope of redemption, prematurely discarding her medical brace and diving back into training, an act that sealed her fate forever from the sport she loved.
Elsewhere, Ho-su's compassion lands him in legal jeopardy by aiding the victim entangled in his client's contentious case. Lee Chung-ku, a seasoned lawyer and Ho-su's long-admired mentor from his university days, swiftly detects his involvement and promptly sidelines him from crucial meetings and ongoing legal battles.
Meanwhile, Mi-ji's perseverance encounters an unexpected barrier when she meets with the elderly restaurant owner, who intends to formally decline the lucrative offer from her company. Undeterred, Mi-ji repeatedly returns, her hands deep in soap and water as she scrubs the restaurant in a heartfelt attempt to sway the woman's decision. But her tireless efforts remain unfruitful, her determination even leading her to stake out the owner at a poetry class—an act that ends in an awkward confrontation and no change in heart.
Seeking counsel, Mi-ji turns to Ho-su, and together they uncover that the restaurant's proprietor is a renowned poet who has been a steadfast benefactor to students from single-parent households, Ho-su among them. During his academic pursuits, Ho-su had personally benefited from her generosity and sponsorship.
Elsewhere, Mi-rae diligently toils at the strawberry farm, her intelligence and keen instincts evident in the meticulous selection of saplings and the nurturing of the harvest. After clocking out, Se-jin offers her a lift home and is astonished by her exceptional driving prowess, all the more remarkable considering her lack of cycling skills.
Back at the law firm, Ho-su finds himself sidelined from a project he had painstakingly contributed to. Despite Chung-ku's directives, Ho-su persists, pleading with his teammates to include him. Ironically, this pleading leads to an unexpected invitation to join them on a triple date, where he bumps into Park Ji-yun, a former high school acquaintance. Realizing the connection, they promptly call Mi-ji to join their gathering, as Mi-rae and Ji-yun had forged a close bond following the conclusion of Mi-ji's athletic career.
Later, Ji-yun chauffeurs Mi-ji to the venerable restaurant. Mi-ji feigns the elderly woman as her grandaunt, but her true intention is to surrender a bathroom key she inadvertently pocketed after one of her unsolicited visits, during which she had been sternly reprimanded.
Returning to the firm, Lee Chung-ku introduces Ho-su to a humanitarian lawyer, suggesting a potential team switch. A heated exchange ensues, with Chung-ku questioning Ho-su's willingness to forsake his principles merely to retain his current position.
Meanwhile, Mi-ji is under immense pressure from her director to ensure the elderly woman's attendance at a crucial redevelopment meeting. Coincidentally, Ji-yun also harbors ambitions to feature the restaurant in her latest project. Mi-ji rushes to the scene, but her heart sinks as she realizes that both she and Ji-yun will confront the old woman, potentially exposing Mi-ji's carefully crafted deception. Yet, to her surprise, the woman playfully adopts the pretense along with her, maintaining a calm demeanor. Once Ji-yun departs, the woman relents and agrees to meet with Mi-ji's company officials, albeit with the intention of politely declining their offer in person. Mi-ji is relieved and grateful, feeling that she has technically fulfilled her directive.
As Mi-ji steps away to retrieve a bathroom key, Ho-su arrives to express his heartfelt gratitude to the elderly woman for sponsoring his education. Deeply touched, she reveals that he is the first person ever to thank her for her kindness. In a gesture of warmth, she prepares a meal for him.
Elsewhere, Se-jin offers a heartfelt apology to Mi-rae, discovering that she had cleaned and organized the warehouse in his absence. He explains that the old chair she had moved held sentimental value; it had belonged to his grandfather, whose farm he now tirelessly manages.
In the climactic scene, Ho-su confides in Mi-ji (whom he still mistakes for Mi-rae), revealing that he has quit his job and is fully committed to supporting her endeavors in the future.