"Nobaku Otaku Sensei" centers on Nobaku Shizuka, a high school teacher who harbors a deep passion for otaku culture, particularly anime, manga, and video games. Despite her professional demeanor at school, Nobaku leads a double life, immersing herself in her hobbies outside of work. Her dedication to otaku interests often leads to humorous and chaotic situations, especially when her students and colleagues inadvertently discover her secret life. The series explores the clash between her professional responsibilities and her personal passions, highlighting the challenges of balancing societal expectations with individual identity.

The narrative frequently delves into Nobaku’s interactions with her students, many of whom are also otaku or have their own unique quirks. These relationships often serve as a vehicle for comedic and heartfelt moments, as Nobaku navigates her role as both a mentor and a fellow enthusiast. Her students, including the earnest and studious Ayaka and the mischievous but kind-hearted Rintaro, provide a diverse cast that enriches the story’s dynamics. The series also introduces other faculty members, such as the strict but well-meaning vice principal and the laid-back art teacher, who add further layers to the school setting.

As the story progresses, Nobaku’s otaku lifestyle increasingly intertwines with her professional life, leading to situations where her hobbies inadvertently influence her teaching methods and interactions. The manga explores themes of self-acceptance, the importance of pursuing one’s passions, and the value of understanding and embracing differences. Through its blend of comedy, slice-of-life elements, and occasional moments of introspection, "Nobaku Otaku Sensei" offers a lighthearted yet thoughtful portrayal of a teacher’s journey to reconcile her dual identities in a world that often demands conformity.