An ordinary high school girl named Kamimuki (voiced by Lynn) was born in a poor family. In order to make money to supplement her family income, she, as a gymnast, decided to participate in a competition called "Competition Girls". Girls wear swimsuits and carry foam boards floating on the water. They use their bodies as weapons and rely on collisions or pushes to make their opponents fall into the water. The winner will receive a huge bonus. The world of competition girls is full of fierce competition. The calm and mature Sayaka Miyata (voiced by Mao Ichimichi), the introverted and shy Aoba Fuune (voiced by Kaede Hondo), and the lively and cheerful Toyoguchi Noone (voiced by Saori Onishi), Kamimuki lives and studies with these girls with different personalities but kind and lovely. They are both companions and opponents to each other. On the clear water, the song of youth full of blood and passion is playing.