Baseball is life for the die-hard competitors in Koshien, Japan’s national high school baseball championship, whose alumni include US baseball stars Shohei Ohtani and former Yankee Hideki Matsui. As popular as America’s World Series, the stakes are beyond high in this single-elimination tournament. For Coach Mizutani, cleaning the grounds and greeting guests are equally important as honing baseball skills, however, demonstrating discipline, sacrifice and unwavering dedication. Director Ema Ryan Yamazaki follows Mizutani and his team on their quest to win the 100th annual Koshien, and, in the process, goes beyond baseball to reveal the heart of the Japanese national character.

2018年，適逢夏季甲子園100週年，更是「平成最後一個夏天」。日本全國近4,000參賽隊伍，即將透過單敗淘汰制，選出56校角逐高中棒球最高榮譽。水谷哲也，橫濱隼人高中棒球總教練，目標制霸全國，始終將球隊擺在家庭之上。他從未見過15歲的兒子打球，也不願訓練他。水谷將兒子送到遠方的花卷東高中，在他的弟子佐佐木洋隊中磨練。佐佐木可謂青出於藍，大聯盟球星大谷翔平、菊池雄星都是他訓練出的高徒。大賽在即，同為甲子園常客的兩校隊伍，將會由哪隊創造奇蹟？

역사적인 제100회 전국고교야구선수권대회에 참가한 감독과 선수들을 가까이 따라가면서 전통과 진보, 강압과 자율 사이에서 균형을 찾기 위해 몸부림치는 일본 사회의 충격적인 단면을 제시한다.