Takagi Kazuma is an elementary school student. Once a top marathon runner, his father is now a loser addicted to drinking and gambling. However, when Takagi's mother suddenly returns for her son, Takagi's father is forced to clean up his act. Can the father-son bond help Takagi regain lost glory and keep his family together?

The story of a boy, Haruho, who grows up aiming for the Grand National, the world's most prestigious horse racing steeplechase, with the passion he inherited from his jockey father.