Hajime no Ippo (also called Fighting Spirit or Knock Out) is one of my favorite mangas of all time. This series is all about boxing that revolves around a noob boxer named Makonouchi Ippo.
(*Spoiler alert* If you are watching the series I might ruin some plot if you continue reading below.)
Ippo starts out as a wimpy high school student that was always being pushed around by his school mates. One time, Ippo was being beaten up when he was suddenly rescued by Mr. Takamura, Japan's reigning middle weight champion. After this episode, Ippo convinced the champion to bring him to their boxing gym so he could train for boxing.
Initially, Ippo only wanted to box so he could exercise. But after meeting his fierce rival Miyata, he began to obsess about finding the true meaning of strength. This time he began to love boxing for the sheer joy of it. Eventually, Ippo began to carve a name for himself in Japanese boxing. He was known as the man with the Dynamite Punch.
His win record and reputation earned him a shot against Mr. Date, Japan's fly weight champion. Though he was not able to beat Mr. Date, he got another shot at the title when he beat another fierce rival, the Tiger of Nanuwa, named Rocky.
(*End of spoiler*)
According to some manga sites, the anime was cut short after Ippo became the champion. But the manga is still on-going in Japan until now. Fans of the manga said that the series is still as good as it was in the anime. To get some manga scanlation of the new issues of the series go here.
I give this series 5 out of 5.