Naruto: Fish World

Before the timeskip, there was a mission Naruto, Sasuke, and Sakura had. It involved a land filled with fish farmers and a defective ninja who is a professional at poisoning things. He already poisoned the river where the fish live. And he poisons the air with his weapon. All of Team 7, even their mentor, is too weak to fight him. Only a young fish farmer can help them.