"Aoi-chan Attack!" centers on Aoi, a high school girl who harbors a secret crush on her classmate, Tsubaki. Aoi's feelings are complicated by her inability to express them directly, leading her to adopt a peculiar method of communication: she writes her thoughts and emotions on sticky notes and secretly places them on Tsubaki's belongings. These notes range from heartfelt confessions to playful remarks, creating a one-sided yet persistent form of interaction. Tsubaki, initially puzzled by the mysterious notes, gradually becomes intrigued by their sender, unaware that Aoi is the one behind them.

The narrative explores the dynamics between Aoi and Tsubaki as their relationship evolves through this unconventional exchange. Aoi's shyness and determination to convey her feelings without direct confrontation drive much of the story's tension and humor. Tsubaki, on the other hand, is portrayed as a kind and observant individual who begins to piece together the identity of the note writer. The series delves into themes of unspoken emotions, the challenges of communication, and the awkwardness of teenage romance.

Supporting characters, such as Aoi's friends and classmates, add depth to the story by providing contrasting perspectives on love and relationships. Their interactions with Aoi and Tsubaki highlight the complexities of navigating emotions during adolescence. The manga balances lighthearted moments with poignant reflections on the difficulties of expressing vulnerability, making it a relatable exploration of young love and self-discovery. The story progresses through a series of vignettes, each capturing small yet significant moments in Aoi and Tsubaki's evolving connection, culminating in a gradual unraveling of their feelings for one another.