Clare, a high school senior who has recently returned to a west coast town, finds herself persuaded by her old friend, Stella, to attend a lively Halloween bash. It is at this party where she encounters Aiden, a charismatic young man whose singing talent shines as he takes over the karaoke stage. Their connection is almost instantaneous, leading them to leave the festivities together for an unplanned date filled with adventure.
Having experienced a transient lifestyle due to her parents’ divorce, Clare has grown accustomed to isolation and has chosen to concentrate on her educational aspirations of becoming a lawyer, seeking to aid those in need. Conversely, Aiden comes from a stable home; both his parents are successful doctors. His desire to pursue a career in music clashes with their expectations for him to follow in their footsteps.
Their journey begins with playful misdemeanors, such as stealing candy from a local store, and joyfully relishing their time at a nearby park. As feelings blossom, a moment arises where Aiden attempts to kiss Clare, but she hesitates, expressing her fears about relationships—stemming from her parents’ own youthful romance that ultimately ended in divorce. In a light-hearted yet serious proposal, Aiden suggests they enter into a "breakup pact," where if they are still together at the end of summer, they will have one final date before parting ways. Clare is intrigued by this unconventional plan, and thus begins their youthful romance.
As summer comes to an end, and with Clare preparing for her road trip to Dartmouth, they attend a barbecue that combines both of their families. Amid the grilling and laughter, they are playfully chided about being naive to consider giving up on love. With a goal to leave a lasting impression, Aiden orchestrates a surprise final date intended to solidify their connection. The night begins with a performance by Aiden's old band—a nostalgic reminder of their first date when he serenaded her, prompting an emotional dance to that very song.
The adventure continues as they make their way to an ice hockey rink, a symbolic location where their first disagreement had taken place. It was there that Aiden had felt the pressure to be perfect, a pressure that clouds their relationship. In a moment of vulnerability, Aiden confesses to his earlier dishonesty, and they rediscover their playful spirits by engaging in a fun game of hockey. Their escapade proceeds to a thrilling speedboat ride, reminiscing about a day filled with water sports where Aiden professed his love for Clare while she effortlessly swam back to their raft after falling off. He treasures that memory by gifting her a keychain shaped like a rocket adorned with a heartfelt inscription.
However, as Aiden's heartfelt gestures of love amplify, Clare finds herself engulfed in doubt. At their Valentine's Day celebration spot, overwhelmed and emotionally strained, she reaches out to Stella for support. When Aiden unexpectedly arrives in a tuxedo for what should have been their romantic evening, the atmosphere is altered by the presence of Stella and Scotty. Clare attempts to conceal her intentions of breaking the romantic mood but is confronted by the reality of their situation.
With honesty on her side, Clare confides in Scotty about her desire for a clean break from Aiden. However, her insecurities resurface as she contemplates how Aiden's acceptance into Berklee could have eased the transition. Their playful antics take a turn when an unexpected alarm prompts a chaotic escape, leaving Aiden injured in the process. At the hospital, Clare discovers that Aiden had not been admitted to Berklee and is infuriated by his lack of transparency. Their relationship becomes strained as tempers flare—she feels deceived and questions whether Aiden even considered their potential future.
As the evening winds on, Aiden reveals his enduring love for Clare, but she finds it difficult to reciprocate, leading to a heart-wrenching farewell. Clare's mother provides her with the clarity necessary to recognize that their relationship needs to be free of predetermined endings. With newfound resolve, she reaches out to Aiden for one final conversation. Together, they wade into the water, confessing their feelings as they swim toward a buoy, a metaphorical representation of their connection.
In a poignant conclusion, Aiden expresses a willingness to embrace the uncertainty that lies ahead, opting to defer his plans for college in Los Angeles to chase his musical dreams. The next day, Clare sets off for New Hampshire, focusing on her education while still keeping tabs on Aiden's music career through social media. Their paths are set to cross once more during Clare's summer break, as they reunite at the playground where their love story began, ready to explore where their journey will take them next.
