"Shinji?" Naruto calls out to me as he enters my office.

He's been training with his team most days, so I haven't seen him around as much. "Yes, Naruto? Something I can help you with?"

"Hey, you know the shadow clone jutsu, right?" he asks me.

"Yes, I know it. What about it?"

"How come I've never seen you use it when you fight?"

"Well," I start. "I isn't a very good combat technique. The shadow clone's main strength is as a multiplier for training. Since you get the clones' memories when they dispel, you can have them train in techniques for you. You can also use them to get information from enemies in a safe way."

Naruto's eyes widen and he says, "Oh! I didn't know that about their memories. But I used the clone technique to beat Mizuki-teme, so it is sort of strong, though."

I shake my head and say, "No, he was just a weakling. Look let me explain this to you. You would think that the shadow clone technique would be a force multiplier, since it literally creates a bunch of copies of you, but the world doesn't work that way. There is a natural law of the universe: the law of conservation of ninjutsu. This law suggests that, in any fight, there is only a finite amount of ninja power available to each side. For this reason, a single ninja is a deadly threat, while an army of them would be mowed down like blades of grass."

And Naruto remembers back to his fight against Kakashi during the real genin test and he knows this to be true.

"So, then, I should use the jutsu to train myself, but not in battle?"

"Well, you can use it against wimps, or if the other side already has a lot of ninjas on their team, but against a strong opponent, don't expect them to be much help. Also, while you can use the technique to practice jutsus or something, you can't use it to train your muscles; that you'll have to do with your real body."

Naruto nods seriously, appreciative of my wisdom. I chuckle a little after he leaves to get back to his training.