Shura Sanjuro (the shinobi with the umbrella-style weapon) is most likely from the Village Hidden in the Rain. This umbrella-style weapon is typically used in that village.
Naruto: What have we got here? Don't move! You better tell me who you are!
Shorasanjo: I'm Shorasanjo, head of the Ninja Dropouts. (Draws umbrella)
Todoroki: You scum!
Shorasanjo: Just hand him over; Gantetsu is with us.
Naruto: Sorry, but that's not gonna happen!
Todoroki: That's it! (Thinking) Akio, I will finally avenge you! (Draws sword)
Naruto: (Runs and knocks Todoroki to the ground) What the heck are you doing?! Stop it! Are you out of your mind?! What were you gonna do just now?!
Naruto: This is ridiculous; they won't even let us see the guy we're supposed to guard.
Lee: They treat us like pests who are in their way.
Naruto: Yeah, well if those Ninja Dropout guys would just attack, then we could show them how amazing we really are.
Sakura: Don't say things like that. We're better off if the Ninja Dropouts never show up at all. It's our mission to get Gantetsu safely to the capital, not to show how amazing we are.
Naruto: Ninja Dropouts?
Tsunade: That's right. It's a group of ninja who've chosen to leave their villages and give up the life of a shinobi to go live in the wild with others like them. They're a band of savage thieves who use their skills to steal what they want.
Sakura: You're serious? They actually use their shinobi abilities to commit crimes?
Tsunade: One of their members was captured yesterday in the Ogii Mountain Pass in The Land of Forests. This particular guy is wanted in just about every village you can think of. (shows Naruto, Sakura, and Lee photograph) He was wandering through the woods when he was captured. His name is Gantetsu.
Sakura: What are you saying? In the end, you're merely beating each other up.
Naruto: It's how men bond with each other.
Lee: That's right.
YTV Airdate: October 17th, 2009
In the United States, this was the last episode to air on Cartoon Network with the remaining 11 episodes unaired on TV, and instead being released straight to DVD. The dubbed version of the anime skipped right to Naruto Shippuden which premiered on Disney XD on October 28, 2009.
Original Episode Title: The Enemy "Shinobazu"
Original Airdate: November 9, 2006
The Shinobazu killed Todoroki's family, and Todoroki saw Gantetsu holding his little brother. This is why he has a grudge against him.
A shinobazu is any type of shinobi that abandons his village or goes wild.
This is the second mission that Naruto, Sakura, and Lee have done alone together (not counting the Konoha 11 arc). The first one was in the 3rd movie.