Three kids who signed up to be ninjas immediately regret it. They'd rather steal snacks from the cafeteria, accidentally destroy school property, and scheme their way out of training than actually learn ninjutsu. The show knows exactly what it is: 20 minutes of pure chaos wrapped in the smallest possible stories, told twice in one sitting, where the punchline lands because the premise is already absurd before the joke even starts.

Three ninja trainees at an academy in the Sengoku Period should be mastering the skills of their trade, but Rantarou, Shinbei, and Kirimaru have other priorities: money, food, and play. Welcome to Ninja Gakuen, where first-year students are called Nintamas, and these three keep failing their classes. Strict teachers such as Doi-sensei and the crossdressing Yamada-sensei try to keep them on track. Meanwhile, the villainous Dokutake ninjas, mischievous girls from the kunoichi class, a band of pirates, and even the students' own families all add to the commotion. Nintama Rantarou is an everyday comedy set at a ninja school. Each half hour is split into short segments, cartoon style, that jump from one silly situation to the next.