Naruto is many things; troublesome, wild, unpredictable, adventurous, untamable, unique. But there's a benefit to being wild and unpredictable; no one has the faintest idea what you're going to do next. NarutoHarem

In a weird coincidence. Naruto stumbles upon Kakashi and Gai getting ready for one of their contests. After watching and being amazed by the strength the two possess. He is inspired to become someone powerful enough that he could end every fight with a Single Punch. This is the Story of how the Leaf's One-Punch Ninja came to be.