Nintama Rantarou

Rantarou, Shinbei and Kirimaru are ninja apprentices in the Ninja Gakuen, where first grade ones are called "Nintamas" (contraction of the words ninja+tama (egg). They must learn everything a ninja must know, but as for our heroes, money, food or playing are more interesting. The series show the everyday adventures of our heroes, segmentated in a cartoon fashion, like 2 small episodes in a 30-min show. The cast also includes the teachers (Doi-sensei and crossdressing Yamada-sensei), nintama kunoichis, evil guys (Dokutake ninjas) and even family members of all the cast...

(Source: Anime News Network)