"Immoral Days of a Virgin Teacher" centers on Aoi Minase, a young and inexperienced teacher who begins her career at an all-girls high school. Aoi is earnest and dedicated to her profession but struggles with her lack of confidence and naivety, which often leads to misunderstandings and awkward situations. Her inexperience extends beyond teaching, as she is also socially awkward and unfamiliar with romantic relationships, earning her the label of a "virgin" in both a literal and metaphorical sense.

The narrative explores Aoi's interactions with her students, colleagues, and the challenges she faces in navigating the complexities of her new role. Her students, a diverse group with their own personalities and struggles, often test her patience and resolve. Some students take advantage of her naivety, while others genuinely seek her guidance. Aoi's journey is marked by her efforts to connect with her students, understand their needs, and grow into a more confident and capable educator.

Throughout the series, Aoi encounters various moral and ethical dilemmas, particularly as she becomes entangled in the personal lives of her students. Her attempts to help them often blur the lines between professionalism and personal involvement, leading to situations that challenge her principles and force her to confront her own insecurities. The story also delves into the dynamics of the school environment, highlighting the pressures faced by both teachers and students in a competitive academic setting.

Supporting characters include fellow teachers who provide contrasting perspectives on education and mentorship, as well as students whose individual arcs intersect with Aoi's growth. The series balances moments of humor and lightheartedness with more serious themes, such as the impact of societal expectations, the importance of empathy, and the complexities of human relationships.

"Immoral Days of a Virgin Teacher" is a character-driven narrative that focuses on Aoi's development as she learns to navigate the challenges of her profession and personal life. The story emphasizes her gradual transformation from a timid and uncertain individual into a more self-assured and compassionate teacher, capable of making a meaningful impact on her students' lives.