Hajime no Ippo - Highly recommended

Ippo Makunouchi is a very shy high school student who never had the
time to make friends because he was always busy helping his mother with
the family charter boat fishing business. Because he kept to himself, a
group of bullies led by Umezawa got into the habit of picking on him.
On one particular day these bullies decided to give him a rather
serious beating, but a middle-weight professional boxer who was passing
by stopped the bullies and took the injured Ippo to the Kamogawa Gym (鴨川ボクシングジム, [i]Kamogawa Bokushingu Jimu[/i][sup][url=http://en.wikipedia.org/wiki/Help:Japanese][color=#0000EE][font=sans-serif][b]?[/b][/font][/color][/url][/sup]),
owned by retired boxer Genji Kamogawa, to treat his wounds. After Ippo
awoke to the sounds of boxers training, the boxer who saved him, Mamoru
Takamura, tried to cheer Ippo up by letting him vent his frustrations
on a sandbag. It was then that they had their first glimpse into Ippo's
talent for boxing. After that incident, Ippo started his regular
training and began his path in [url=http://en.wikipedia.org/wiki/Japan]Japan[/url]'s professional boxing.
The story focuses heavily on character development, even during the
matches something is learned about the fighters. Ippo and his friendly
rivalry with Miyata is the main draw in the early part of the series.
That later changes to Ippo's path towards the Japanese Featherweight
Championship and eventually the world championship. Along the way we
are given glimpses into the other side character's pasts, motivations,
relationships to others and current boxing trials.
The anime series has two spin-off movies that were actually part of
the manga. Champion Road, which takes place after Ippo becomes the
Japanese Featherweight Champion and showcases his first defense of the
title, and Kimura Vs. Mashiba, which pits one of Ippo's upper classmen
(Kimura) against the Japanese lightweight champion Mashiba (the brother
of Ippo's love interest).

source: http://en.wikipedia.org/wiki/Hajime_no_ippo