Season 1 of Blackboard premiered on April 5, 2012.

In 1947, Shirahama Shohei, who has returned from the battlefront, teaches again at a junior high school in Ota Ward. He is puzzled by the radical transformation that Japanese education has undergone because of the war defeat, but concerned for the welfare of his former students, he holds a class reunion. Before Shohei departed for the battlefront, he taught that "Japan has no future unless it wins the war" and his students had stared at the word "future" on the blackboard with burning gazes. Believing in that word, they had excitedly volunteered to be child soliders. In the end, they lost healthy bodies and minds, and there were even those who lost their lives. Shohei is tormented by regret and dread. How does he talk about the word "life" on the blackboard?

In 1980, Shirahama Shohei's student, Goto Akira, returns to the junior high school at Ota Ward to be a teacher. His alma mater which brings back fond memories is in the grip of school violence. The thunderous roar of motorbikes of rabble-rousing delinquents, windows smashed by bats, and that classroom blackboard with the words "Go and die" in red graffiti. While the teachers turn their backs on the school's most problematic student, Furusawa Yukari, Goto stops the violence of the girl who persistently puts her life at risk. That approach draws criticism and he is labelled a teacher who uses physical force. However, he also conveys the importance of life, having experienced it himself.

In 2011, the junior high school in Ota Ward experiences a complete breakdown in classroom discipline. Takizawa Momoko, an English teacher in charge of the third-year students, writes the words "My dream" on the blackboard, but it is in vain for no one participates in the lesson. Even so, Momoko perseveres in reaching out to her students. Yokote Ryoko, the present school principal who was once colleagues with Goto Akira, is supportive of her. One day, Momoko learns that Omiya Masaki, an extremely defiant transfer student, has not received adequate education because of his family situation, and gives him personal coaching, but she is critised for forming an inappropriate relationship with a student. How does she talk about "love", "dreams" and the "meaning of school"?