"Ensembukubu Stars!" is a manga series that revolves around the activities of the Ensemble Club, a group of high school students dedicated to performing and promoting ensemble music. The narrative centers on the club's efforts to maintain its existence and grow its membership in a school where extracurricular activities are highly competitive. The story begins with the club facing the threat of disbandment due to a lack of members and interest. To prevent this, the remaining members, led by the determined and passionate club president, embark on a mission to recruit new members and revitalize the club.

The main characters include the club president, who is deeply committed to the ensemble and serves as the driving force behind the club's revival. Another key character is a talented but reluctant musician who initially joins the club out of obligation but gradually develops a genuine interest in ensemble performance. The group also includes a quirky and energetic member who brings creativity and enthusiasm to their activities, as well as a more reserved and analytical member who provides balance and strategic thinking. Together, they navigate the challenges of recruiting new members, organizing performances, and competing with other clubs for resources and recognition.

The plot progresses through a series of episodic arcs, each focusing on specific challenges or events, such as preparing for a school festival, participating in competitions, or overcoming internal conflicts. The narrative emphasizes themes of teamwork, perseverance, and the transformative power of music. As the club grows and evolves, the characters develop deeper bonds and a stronger sense of purpose, culminating in their efforts to achieve a significant performance milestone that solidifies their place in the school community. The series balances lighthearted moments with more serious reflections on the importance of passion and dedication in pursuing one's interests.