"Positive Teacher" centers on the life of Akira Tachibana, a young and idealistic teacher who begins his career at a high school filled with students facing various personal and academic challenges. Akira is determined to make a positive impact on his students, often going beyond his duties to help them navigate their struggles. His approach is unconventional, emphasizing empathy, understanding, and encouragement over strict discipline, which sometimes puts him at odds with the school administration and more traditional colleagues.

The narrative explores the lives of several students, each with distinct issues. Among them is Yuki, a talented but socially withdrawn artist struggling with self-doubt; Hiroshi, a delinquent with a troubled home life who masks his pain with defiance; and Rina, an overachiever burdened by immense pressure from her family. Akira’s interactions with these students form the core of the story, as he helps them confront their fears, build confidence, and find their own paths.

The series also delves into Akira’s personal growth as he learns from his students and reflects on his own past. His dedication to teaching is tested by bureaucratic obstacles, societal expectations, and the emotional toll of his work. Despite these challenges, Akira remains steadfast in his belief that education is not just about academics but also about nurturing the potential within each individual.

Supporting characters include fellow teachers who represent a spectrum of educational philosophies, from rigid traditionalists to progressive thinkers. These interactions highlight the broader debates within the education system, adding depth to the narrative. The story balances moments of heartfelt encouragement with realistic portrayals of the struggles faced by both students and educators, creating a nuanced exploration of the teacher-student dynamic.