Yes, such fanfictions exist. In these fictional scenarios, Naruto might kill himself because of Sasuke for several reasons. Naruto's whole life has been centered around Sasuke to some extent. If he feels that he has failed in his mission to bring Sasuke back to the right path and that the situation has become so dire that the only way to atone for his 'failure' is through his death, he might do it. Also, if Sasuke were to cause harm to someone Naruto holds dear, like the village or his other friends, and Naruto feels powerless to stop him in any other way, he could choose to end his own life as a last resort.
It could be a miscommunication. Maybe Hinata said something that Naruto completely misinterpreted in a very negative way, like she didn't love him anymore or she blamed him for something major. This misunderstanding could be so great that Naruto loses hope and takes his life.
There could be fanfictions with that plot. It could be that in the fan - created world, Sakura has been really cruel to Naruto's feelings. She might have chosen someone else over him repeatedly and publicly humiliated him for his feelings, which could shatter Naruto's self - esteem and make him feel like there's no way out but to end his life.
One common theme is unrequited friendship. Naruto's deep - seated friendship for Sasuke not being reciprocated in the way he hoped could lead to his downfall. Another theme could be the idea of sacrifice. Naruto may sacrifice himself believing it will save Sasuke from his dark path.
One possible reason could be a miscommunication that escalates out of control. Maybe Sasuke is on a path that Naruto believes is too dangerous for the world, and Naruto, in an attempt to stop him, accidentally kills him. For example, Sasuke might be about to use a powerful and uncontrollable jutsu that Naruto fears will destroy the Uchia compound and much more, so he acts in haste.
One possible reason could be that Sasuke might have gone too far in his pursuit of power even after the war. He could have been a threat to the newfound peace in the ninja world, and Naruto, as the protector of peace, might have felt he had no other choice.
One possible reason could be extreme heartbreak. If in the fanfic, Sasuke does something unforgivable like completely rejecting Naruto's long - held friendship and trust, it might push Naruto over the edge. He has always placed great importance on his bond with Sasuke, and if that is shattered in a way that seems irreparable, it could lead to his self - destruction.
One possible reason could be a sudden and extreme corruption of Naruto's character. Maybe he is influenced by some dark and powerful force that makes him turn against his friends. Another reason might be a misinterpretation of a prophecy or some kind of mind - control situation.
One possible reason could be a misunderstanding. Maybe Sasuke is framed for something really bad, and Naruto, in his anger and sense of justice, lashes out without knowing the truth. For example, if there's a false rumor that Sasuke has attacked the village again, Naruto might be quick to act.
Well, it could be that he has lost all hope. In the fanfiction world, if the situation becomes so dire that he sees no way out for himself or the people he loves. For example, if Voldemort manages to gain complete control and Harry Potter thinks his sacrifice by taking his own life might be the ultimate solution to break Voldemort's power. He might also be suffering from post - traumatic stress after all the battles and losses, leading him to this extreme decision.
Well, in such a fanfiction, it could be due to a combination of factors. His isolation in Grimmauld Place might have taken a huge toll on his mental state. He might have felt like a burden to his friends, especially Harry. And the lack of any real future prospects, given his fugitive status and the ongoing battle against Voldemort, could have pushed him over the edge into taking his own life.