"My Senpai Is Annoying" is a workplace romantic comedy manga that centers on the dynamic between Futaba Igarashi, a petite and hardworking office worker, and her tall, boisterous senior colleague, Harumi Takeda. Futaba often finds Takeda's loud and overbearing personality irritating, especially since his towering stature and booming voice make him impossible to ignore. Despite her initial annoyance, Futaba gradually begins to appreciate Takeda's genuine kindness, reliability, and unwavering support in both professional and personal matters. Their relationship evolves through a series of humorous and heartwarming interactions, blending workplace challenges with lighthearted romantic tension.

The story is set in a typical office environment, where the daily routines and tasks of the characters provide a backdrop for their growing bond. Futaba struggles with being underestimated due to her small stature and youthful appearance, often mistaken for a high school student. Takeda, on the other hand, is a dependable and well-liked figure in the office, though his loud demeanor sometimes causes misunderstandings. Their colleagues, including the observant and sharp-tongued Sakurai and the cheerful yet clumsy Kazama, add depth to the narrative, contributing to the comedic and slice-of-life elements of the series.

The manga explores themes of personal growth, mutual respect, and the gradual development of romantic feelings within a professional setting. Futaba and Takeda's relationship is marked by a balance of humor and sincerity, as they navigate the challenges of their jobs while slowly becoming more attuned to each other's feelings. The series avoids melodrama, instead focusing on the subtle, everyday moments that bring the characters closer together. Through its relatable workplace scenarios and endearing character dynamics, "My Senpai Is Annoying" offers a charming and light-hearted portrayal of modern office life and budding romance.