Mirai - Blackboard

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?