Ninja Brat

A kid who aspires to be a Ninja, but he or she has a long way to go and a lot to experience before he or she becomes into a real ninja. Of course, some of them can already be Ninja and kick ass.

Compare Kid Samurai and The Gunfighter Wannabe. Contrast Child Soldiers.

Examples of Ninja Brat include:

Anime

Naruto started out as this.
- Also, Konohamaru.
Nintama Rantarou.
The Narutaki Twins from Mahou Sensei Negima could be this trope.
Black*Star from Soul Eater may qualify as this.
Shinobu from Ninja Nonsense.
Ninja Hattori-kun.

Comic Books

The Teenage Mutant Ninja Turtles, anyone? Well, to be fair, Michelangelo seems to fit this trope better in the later incarnations..

Film

All of the new students attending at Ninja Academy.
Spritle in the film version of Speed Racer, but he doesn't pull it off very well.
The three protagonists from the Three Ninjas film series.
The Filipino film, Ninja Kids.

Live-Action TV

Supah Ninjas

Video Games

Yuffie from Final Fantasy VII.
The ninja kids from the 3rd-gen and 4th-gen Pokémon games.
Yomiko in Exit Fate, possibly.
Jajamaru, from the Jajamaru-kun video game series.
Izuna, from Izuna Legend of the Unemployed Ninja.
Kid Niki, in Kid Niki, Radical Ninja.
Kat and Ana from the Wario Ware series.
Kay Faraday of Ace Attorney Investigations: Miles Edgeworth. As Edgeworth muses repeatedly, while she claims to be a Phantom Thief in training, she seems to actually want to be a ninja.
Mini Ninjas - all of the playable characters are kids (preteens at the oldest)
Hokutomaru from Garou: Mark Of The Wolves.

Web Comics

In Marilith, Yulia's granddaughter Monika wants to be a ninja when she grows up.
Robin's brother in The Wotch, due to being a Naruto fan.

Western Animation

Garu and Tobe from Pucca.