The film explores the unusual love story between a male engineering student named Gyeon-woo and an unnamed girl, often referred to simply as "the Girl." Gyeon-woo finds himself struggling in the realm of romance, unable to connect with anyone, as their contrasting personalities challenge the traditional norms of masculinity and femininity, particularly within the context of Asian societies.
During a casual evening out with friends, Gyeon-woo receives an unexpected call from his mother urging him to visit his aunt for a potential date. On his way to the train station, he encounters a drunk girl teetering dangerously near the platform's edge. Acting quickly, he saves her from a potentially fatal fall, yet his feelings are mixed as he finds her inebriation off-putting. After a series of embarrassing incidents on the train—where she vomits on a fellow passenger and faintly calls him "honey"—Gyeon-woo leaves her slumped on a bench, but ultimately decides to take her to a hotel for safety. Unfortunately, their escapade is cut short when the police raid the hotel and Gyeon-woo finds himself behind bars, only to be released the next day.
To his surprise, the Girl contacts Gyeon-woo, insisting they meet to discuss the prior night's events. Over drinks of soju, she reveals her recent breakup, resulting in an emotionally charged second trip to the same hotel. From this moment onward, their relationship spirals into comedic chaos as the Girl frequently disrupts Gyeon-woo’s life. She becomes a fixture in his daily routine, even pulling him from class to proclaim him the father of her supposed aborted baby. Her erratic behavior fluctuates between excitement and violence, yet Gyeon-woo tolerates her antics, attributing her cruel treatment as a sign of affection.
With aspirations of becoming a scriptwriter, the Girl shares numerous screenplays with Gyeon-woo, including an action flick titled "The Demolition Terminator," where she heroically rescues him, and a bizarre twist on a Korean short story, ultimately demonstrating her struggle with their relationship dynamic. In one of her tales, the Girl, now depicted from a futuristic perspective, urges Gyeon-woo to confront the challenges of their unconventional bond.
Determined to show her he cares, Gyeon-woo plans a sweet surprise for her birthday at an amusement park, which unexpectedly turns into a hostage situation with a troubled soldier. Demonstrating his ability to empathize, Gyeon-woo helps resolve the soldier’s crisis, inadvertently strengthening his bond with the Girl. However, their happiness is tested as her family disapproves of Gyeon-woo, further complicating their connection.
As Gyeon-woo perseveres through the ups and downs, the Girl eventually calls on him to bring her a rose to mark their 100-day anniversary. He obliges, leading to an emotionally touching moment when he sneaks into her piano recital. The scene showcases Gyeon-woo's heartfelt gesture amidst the applause of her classmates, starkly contrasted by future interruptions with her parents, who insist on their separation.
After a short period of silence, the Girl intriguingly invites Gyeon-woo to accompany her on a blind date, introducing him to her date in a way that highlights her deep-seated feelings for him. As she reconnects with Gyeon-woo throughout the dinner, their deep understanding of each other surfaces, eliciting her mysterious but palpable emotional turmoil. This leads to an exodus as she abruptly departs to search for Gyeon-woo, resonating with her earlier experiences and prompting a race against time at a subway station.
In an emotional twist, they decide to deepen their bond by burying a time capsule filled with letters under a tree, promising to reunite after two years. During this time, Gyeon-woo grows determined and takes strides to better himself, channeling his experiences with the Girl into writing that garners attention from movie producers—fulfilling a dream he believes she would cherish.
However, their anticipated reunion is met with disappointment when the Girl fails to appear, leading Gyeon-woo to uncover the depth of her emotional struggles through her heartfelt letter: the essence of her angst traces back to the loss of a previous boyfriend. Enlightened by her history, Gyeon-woo processes his own trajectory of self-improvement while grappling with the complexity of her feelings.
A year later, when the Girl finally returns to the tree, she discovers Gyeon-woo’s absence. Their paths continue to cross in serendipitous moments, only to be thwarted by circumstance. Eventually, fate orchestrates a blind date between the Girl and Gyeon-woo, facilitated by the mother of her late boyfriend, leading to a rekindled connection defined by the weight of what they’ve endured separately.
In a beautifully bittersweet moment, as the camera pans out, we find the two holding hands beneath the table while gazing lovingly at each other, encapsulating the profound nature of their journey back to one another.
