The popularity of the JRA (Japan Racing Association) is becoming established through daily media coverage and TV broadcasts. However, on the other hand, there is also "horse racing" that is not shown on TV! At the Kawasaki Horse Racing Gengoromaru Stables, there is a story about Gengoromaru, his father who is about to end his life as a trainer, and who is in charge of the stable's future. There was a child, Akira, who was trying. An injured racehorse, Grand Sanryu, was kept there. There is only a 1% chance of a comeback, but Akira and Grand Sanryu's tenacity will cause a miracle!