Maybe a set of shuriken with special properties. For example, they could be made of a rare metal that makes them more durable and able to fly farther and with more accuracy. In the fanfiction, these shuriken could be a key weapon for Naruto in his battles in the Wave arc.
Well, he might get a chakra - enhanced katana. It could be really cool as it can cut through almost anything with the added chakra power.
Another possibility is a unique kunai. It could have some sort of sealing jutsu inscribed on it. This would allow Naruto to use it not just for stabbing or throwing, but also for sealing away small amounts of chakra or even small objects. This would give him an edge in combat as he could disrupt his opponents' chakra flow or steal some of their chakra using this special kunai.
Chapter 448, "Has Jiang Li Gone Crazy?!", is the clearest early answer because it turns World Encyclopedia's situation into a concrete plot event. The chapter gives readers a real answer by opening on Yu Li still wanted to persuade her, "Why not keep everything?
Chapter 251, "It seems that going on a transformation show is really useful!", is the clearest early answer because it turns Flash Change's situation into a concrete plot event. Early on, If Du Qinglian was somewhat angry just a moment ago, now she was....
Chapter 562, "So You Are Not First, But Last?!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter gives readers a real answer by opening on After they finished preparing the fish, Guo Xing and Luo Xuan got...
Chapter 436, "Do You Remember Brother Daniu by Daming Lake?", is the clearest early answer because it turns Sister Li's situation into a concrete plot event. The chapter gives readers a real answer by opening on Yu Li took the object that resembled a stone axe and weighed it in...
Chapter 166, "Daniu Gets Jealous!", is the clearest early answer because it turns Zhou Yi's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Only after everyone in the small courtyard had left, did Zhao Lang...
Chapter 432, "Return to the Homeland!", is the clearest early answer because it pushes Zhou Xu into a new phase or setting. The chapter turns that into something concrete by moving from Jiang Li had also received the updated rankings. to He looked at the owner with a hint of surprise..
Chapter 576, "The Electronic Pickles are Gone!", is the clearest early answer because it turns Guo Xing's situation into a concrete plot event.
Chapter 510, "The Fake Young Master", is the clearest early answer because it turns Shang Shaobai's situation into a concrete plot event. It opens with Ever since that night's family banquet, Gu Qiang hadn't slept soundly...
Chapter 374, "From Now On, Jiang Li Calls the Shots in Golden Sand!", is the clearest early answer because it turns Of's situation into a concrete plot event. Early on, Jiang Li's bold behavior infuriated Jin Siyue, but it also succeeded....