"Kimi to Koi ni Ochiru Mahō de" centers on the lives of two high school students, Shizuku and Ritsu, whose relationship takes an unexpected turn due to a magical mishap. Shizuku, a reserved and studious girl, harbors feelings for Ritsu, her childhood friend and classmate. Ritsu, on the other hand, is outgoing and popular but remains oblivious to Shizuku's emotions. The story begins when Shizuku discovers a mysterious book of magic spells in the school library. Hoping to express her feelings, she attempts a love spell, but it backfires, causing her and Ritsu to switch bodies.

The body-switching incident forces Shizuku and Ritsu to navigate each other's lives while searching for a way to reverse the spell. Shizuku must adapt to Ritsu's social and athletic lifestyle, while Ritsu experiences the pressures of Shizuku's academic responsibilities and introverted nature. As they spend time in each other's shoes, they gain a deeper understanding of one another's struggles and perspectives. The situation becomes more complicated when their interactions with classmates and friends reveal hidden emotions and misunderstandings.

Throughout the series, the two protagonists work together to uncover the origins of the magic book and the conditions required to break the spell. Their journey is marked by moments of humor, tension, and self-discovery as they confront their insecurities and feelings. The narrative explores themes of identity, empathy, and the complexities of relationships, blending elements of romance, fantasy, and slice-of-life. As Shizuku and Ritsu grow closer, their bond evolves beyond friendship, raising questions about the nature of their connection and the possibility of a deeper relationship.

The supporting cast includes classmates and friends who play pivotal roles in the protagonists' lives, adding layers to the story through their interactions and subplots. The manga balances lighthearted moments with emotional depth, creating a narrative that resonates with readers through its relatable characters and engaging premise. The resolution of the body-switching dilemma and the development of Shizuku and Ritsu's relationship form the core of the story, culminating in a heartfelt exploration of love and self-acceptance.