"Koi Suru Otome no Renai Keikaku" centers on the romantic and comedic misadventures of a group of students at an all-girls school, focusing on their attempts to navigate love and relationships. The protagonist, Rinko Tamaki, is a shy and reserved girl who harbors a secret crush on her classmate, the popular and outgoing Sumireko Sanshokuin. Sumireko, however, is oblivious to Rinko's feelings and is more interested in pursuing her own romantic endeavors, often involving elaborate and unconventional plans.

The narrative unfolds as Rinko, along with her friends, becomes entangled in Sumireko's schemes to win the affection of various love interests. Sumireko's plans are frequently over-the-top and comically flawed, leading to chaotic and humorous situations. Despite her eccentricities, Sumireko's genuine enthusiasm and determination often bring the group closer together, even as they struggle to keep up with her unpredictable antics.

Supporting characters include Rinko's close friend, Nao Chikura, who provides a grounded counterpoint to Sumireko's exuberance, and other classmates who contribute to the series' dynamic and lighthearted tone. The interactions between the characters are marked by a blend of humor, misunderstandings, and heartfelt moments, as they explore themes of friendship, self-discovery, and the complexities of young love.

The manga balances comedic elements with moments of emotional depth, portraying the characters' growth as they confront their insecurities and learn to express their feelings. The story progresses through a series of episodic arcs, each focusing on different romantic pursuits and the evolving relationships within the group. The interplay between Rinko's quiet longing and Sumireko's bold, often misguided attempts at romance forms the core of the narrative, creating a engaging and entertaining exploration of love and friendship.