I'm not sure if there's a super - popular 'Naruto punch Sakura' fanfic specifically. There are so many Naruto fanfics out there that it's hard to single out one with this exact scenario as being the most popular. However, in the vast expanse of fan - created Naruto stories, it's possible that there are some that feature this plot point.
A reason could be that Sakura says something really hurtful to Naruto about his dreams or his abilities. Naruto, who has always been sensitive about those things deep down, might lose his temper and punch her.
Perhaps there was some sort of dark influence at play. In the world of Naruto, there are often dark forces and genjutsu (illusion techniques). It's possible that Naruto was under the influence of a genjutsu that made him see Sakura as a threat, so he punched her in self - defense without realizing it was an illusion.
Well, one possible consequence could be that Naruto is seriously injured. Maybe he has a broken bone or gets knocked out cold. It could also lead to some sort of rift between them, with Naruto feeling betrayed by Sakura's overly aggressive action.
Well, Kurama might train Naruto by teaching him how to better control and access chakra. Since Kurama has a vast amount of chakra, it could show Naruto unique ways to harness and use it. For example, it could guide Naruto in creating more powerful and complex jutsu by using their combined chakra in a more efficient way.
The Kurama Brothers could be entities that have a similar origin to Kurama. They might have been part of the same chakra - based creation in the Naruto universe. They could possess some of Kurama's traits like great power and a connection to the natural energy in the world. They are often depicted as having their own personalities, with one being more hot - headed and the other more calm and calculating. Their relationship with Naruto usually involves them using their powers and knowledge to help Naruto grow as a ninja and a person. They might also have their own goals and motives that are intertwined with Naruto's journey.
One idea could be that Sakura, with her medical ninja skills, discovers a way to communicate with Kurama while Naruto is in a deep meditative state. She wants to understand more about the tailed beast's power and how it affects Naruto.
For Naruto, it would be a whole new experience. He'd be constantly trying to communicate with the mecha Kurama, learning its quirks. Shikamaru might be the one thinking about the strategic uses of mecha Kurama in battle. He'd be coming up with plans on how to best utilize it. As for Kurama, he could be in an internal struggle. Part of him would want to stay relevant in Naruto's battles, while another part would be curious about this new mechanical version of himself and how it could help Naruto in the long run.
Kurama might become angry at first. He's a powerful being and being neglected would likely wound his pride. He could start causing some minor disruptions inside Naruto, like making it harder for Naruto to access his chakra.