In Toshio Nakamura's school essay, he discusses how in playing the Yu-Gi-Oh! card game he learned about the importance of cooperation and sportsmanship. This directly relates to the central or main idea of the final paragraph of his essay, which emphasizes the importance of working together in order to create a better world. He states, "If everyone could just cooperate with others like we do in the Yu-Gi-Oh! game, then people would understand each other better and our society as a whole would benefit. A better world is possible if we all could get along and work together." Here, Nakamura uses his own experience with the Yu-Gi-Oh! game to promote understanding and cooperation amongst people, which is the main idea of his essay.