History's Strongest Disciple Kenichi
Summary:
Shirahama Kenichi is an average student who has earned the nickname "Weak Legs" from always getting bullied. One day he meets a cute girl named Furinji Miu who helps him build the courage to begin training at a mysterious dojo where she lives. Here Kenichi faces intense training from masters of many different martial arts styles as he attempts to become stronger.

This anime is realy funny, I can't remember the last time I lol'ed in real life watching anime. For like 5 minutes.
There are 50 episodes, each one is 30 minutes.
The anime gets even better towards the end.