"Kimi to no, Hajimete" centers on the evolving relationship between two high school students, Yui and Haruto, who navigate the complexities of first love and personal growth. Yui, a reserved and studious girl, finds herself drawn to Haruto, a popular and outgoing classmate, after a chance encounter. Their initial interactions are marked by awkwardness and misunderstandings, but as they spend more time together, a genuine connection begins to form.

The narrative explores their journey from tentative acquaintances to close friends, and eventually, romantic partners. Yui struggles with her insecurities and fear of rejection, while Haruto grapples with the expectations placed on him by his peers and family. Their relationship is tested by external pressures, including misunderstandings, rivalries, and the challenges of balancing school life with their growing feelings for each other.

Supporting characters, such as Yui’s best friend, Aya, and Haruto’s childhood friend, Riku, play significant roles in shaping the story. Aya provides emotional support and encouragement to Yui, while Riku’s presence introduces moments of tension and introspection for Haruto. The dynamics between these characters add depth to the central relationship, highlighting themes of trust, communication, and self-discovery.

The manga delves into the emotional nuances of young love, portraying both the joys and struggles of navigating a first relationship. Through its focus on character development and interpersonal relationships, "Kimi to no, Hajimete" offers a heartfelt exploration of adolescence and the transformative power of love.