Friendship. Effort. Victory! The story centers around the life of a young boxer named Ryuji Takane and his sister Kiku, who is his coach. Ryuji and his sister both inherited their father's talent for boxing with Ryuji inheriting his strength and techniques while Kiku picked up his talent for analysis and strategy. In the past, their father was a famous boxer. Ryuji and Kiku went away from home to train and become famous in order to help their lonely mother. On the way to stardom, they have to defeat the strongest challengers all over the world. The work that solidified the themes of Weekly Shonen Jump. Those themes being Friendship, Effort, and Victory!