Korobi is a ninja from Sunagakure who serves under Gaara, alongside Yaoki. The two were assigned to work with Gaara on a mission to take down a bandit group operating between the Sand and Leaf villages—the same job Team 7 happened to get sent on.
Korobi comes across as nervous and anxious, largely because he's intimidated by Gaara's volatile nature and killer instinct. Things changed after the Sand Village's invasion attempt, though, and Gaara became less of a threat. When Gaara fell into a trap set by Suna's assassination squad, he ordered Korobi and Yaoki to flee. That's when Naruto caught up with them and learned what happened. He immediately called them out for abandoning Gaara—which made both of them question whether they even qualified as his friends in the first place.
Despite their doubts, Korobi and Yaoki stepped up and helped Naruto rescue Gaara anyway. After the mission wrapped up, Gaara asked what they'd told Naruto about him. They happily revealed they'd called themselves his friends, and this time they actually meant it.
Content compiled by AnimeList.moe from publicly available sources.
