After an absence of four years Kinpachi Sensei, everyone's favorite teacher, returns to the television screen in a new series. When the series first went into production in 1979, delinquency and on-campus violence were big social problems. Over the years, the pressing problems became truancy and bullying, and more recently, disorderly conduct in classrooms and children with explosive tempers. Kinpachi Sensei returns to the classroom to help teenagers caught between childhood and adulthood, who suffer many social and emotional strains.

かつては“非行”と“校内暴力”が大きな問題だったが、時代とともに「不登校」や「いじめ」が学校を席巻し、その後「学級崩壊」と「突然キレる子ども」が新たな火種も生まれた。今シリーズでは少子化の波を受け、桜中学の校内に老人介護施設が併設され、“死”と向かい合って生きる高齢者と、時おり死に憧れる中学生が同じ屋根の下で毎日過ごすことになる。子供から大人への重要な15歳という多感な世代を相手に、50歳になった金八は何を思い、何を語りかけるのか。