"Apple-Cheek Love" centers on the life of Yui, a high school student who struggles with self-esteem and social anxiety. Yui’s insecurities stem from her round, rosy cheeks, which she perceives as a flaw, earning her the nickname "Apple-Cheeked Yui" among her peers. Despite her efforts to blend into the background, her life takes an unexpected turn when she encounters Haruto, a popular and confident classmate known for his charm and academic achievements.

Haruto, intrigued by Yui’s quiet demeanor and unique appearance, begins to take an interest in her. His persistent attempts to befriend her initially unsettle Yui, who is unaccustomed to attention. Over time, their interactions deepen, revealing Haruto’s own vulnerabilities and insecurities beneath his confident exterior. The narrative explores their evolving relationship, as Yui gradually learns to embrace her individuality and Haruto finds solace in her genuine nature.

The story delves into themes of self-acceptance, personal growth, and the complexities of human connection. Supporting characters, such as Yui’s close friend Aya and Haruto’s childhood friend Riku, add layers to the narrative, providing contrasting perspectives on relationships and self-worth. The manga balances lighthearted moments with emotional depth, portraying the challenges of adolescence and the transformative power of mutual understanding.

As the plot progresses, Yui and Haruto navigate misunderstandings, external pressures, and their own fears, ultimately forging a bond that encourages both to confront their insecurities. The series concludes with a sense of resolution, emphasizing the importance of self-love and the impact of meaningful relationships on personal development.