In 1997, Ai, Buffy Chen, struggles with her high school entrance exam and reluctantly enrolls in the night program of the prestigious First Girl's High School under her mother's pressure. She sits among day students during their freshman year, where she meets her deskmate, Min Chloe Xiang, who shares her interests. Although the day students often feel superior, Min reassures Ai that she isn’t elitist, and the two quickly become best friends, forming a quiet but steadfast bond that helps Ai navigate a world that feels split between two different tracks.
To support her family after her father’s passing, Ai works part-time at a table tennis coaching school on Sundays to help repay their debt. Not long after the semester starts, she meets Luke Bruce Chiu, a wealthy student from another prestigious school who is new to table tennis. Luke is assigned to Ai for coaching, and her growing skill impresses him enough to develop feelings beyond admiration. A night out changes their dynamic: Min invites Ai to skip class to watch a basketball match, and Ai injures herself while sneaking off campus. To dodge consequences, Min proposes they swap uniforms so Ai can pass as a student from the other program. Ai’s initial fear gives way to a surprising confidence as she pulls off a few successful disguises, cementing the pair’s improvisational bond.
As the semester progresses, Min arranges another skip-day to introduce Ai to a boy she admires—Luke. Min presents Ai as her classmate, and Luke immediately recalls Ai from their table tennis encounters. The trio grows closer, and Luke begins to visit the table tennis school more regularly, where they even play doubles together. After a victorious match, their coach invites them to a competition, and the pair trains weekly, drawn together by shared goals and a growing mutual admiration. When Luke asks Ai out on a date, she tweaks her uniform’s class label to keep Min from sensing their closeness. Jealousy flares in Min, who schemes to expose Ai by visiting Luke’s mother’s gallery. There, Min cues Ai when Luke’s mother mentions the night program, hoping Ai will react emotionally; things take a sharp turn when a university professor— whom Ai falsely claims as a mentor—reveals she doesn’t know Ai, exposing Ai’s concealed identity. Heartbroken, Ai leaves in tears.
The next day, Ai returns her uniform to Min and quits her job at the table tennis school to avoid Luke’s embarrassment. Ai’s mother, Chin Chi, discovers the academic reports Ai has been hiding, and a heated argument erupts as Ai accuses her mother of forcing her into the night program. A renewal of trust seems distant, but life takes another turn when Ai is promoted to third year and unexpectedly runs into Luke again during the school’s open day. Luke openly confesses his love for Ai regardless of their different worlds, but Ai insists they come from separate backgrounds and that the truth of their circumstances might keep them apart.
Meanwhile, Ai’s uncle falls ill, prompting her mother to visit him, and soon a massive earthquake tests the family. Ai rushes home to check on her sister, who is found safe under a cupboard, and the siblings reconcile once their mother returns. While cleaning up after the quake, Ai finds a keychain that resembles Min’s, which unsettles her. Rushing to Min’s class, she discovers Min is unharmed, and the long-silent deskmates reconnect, sharing their struggles and finding a renewed bond.
Determined to secure a future, Ai dedicates herself to the university entrance exam, and her hard work shows in steady improvements. During the exam, Luke steps forward in a bold, selfless gesture, giving up his own admission quota to join Ai’s world. The two reconcile, exchange lucky charms, and reaffirm their commitment to each other and to Ai’s education. In the end, Ai receives a college offer that feels right for her, and she celebrates her 18th birthday with Min and Luke, glad to face the next phase of life with the people who stood by her through the ups and downs.
