Shimizu Minato (voiced by Uemura Yuto) was once a water polo player, but due to an accident, he decided to give up his beloved water polo in the third year of junior high school. After entering high school, Minato met a boy named Oka Eitaro (voiced by Nishiyama Kotaro) by accident. Eitaro was a former schoolmate of Minato, so he knew the tragic stories that happened to Minato very well, and he also longed to be able to attend the same high school as Minato. Jojima Ryo (voiced by Kimura Subaru) is the president of the water polo club. After his painstaking persuasion, Minato finally agreed to join the water polo club. Amihama Hidego (voiced by Saito Souma), who was once a swimming expert, Ejiri Takeichi (voiced by Furukawa Shin), who is very impulsive and carefree, and Inomata Baba Yarofuyo (voiced by Hatakenaka Yu), who is gentle and calm, made friends quickly at school and regained his passion for water polo.