This book is also called: "The Legend of Counterattack: The Traveler's Different Path to the Ninja World"
As soon as the protagonist traveled through time, he fell into the maelstrom of the Naruto world. Orochimaru, mysterious organizations, etc., Came to cause trouble one after another. But our protagonist is not afraid. He says, "My fate is up to me, and the ninja world must listen to my advice."