Well, it might start with Naruto distancing himself from his friends. He stops going on missions with them, and he doesn't show up at their usual gathering places. For instance, he might avoid Ichiraku Ramen, which was always a place of connection for him and his friends.
When Naruto closes his heart, the fanfic could show his internal struggle. He might have flashbacks to all the good times with his friends and then feel guilty for pushing them away. But at the same time, he feels like he has no other choice. His daily routine would change completely. Instead of his usual energetic self, he becomes a loner. He spends his time alone in places like the forest on the outskirts of the village, brooding. His appearance might even change, with a more sullen look on his face. And as his friends try to get through to him, they might discover new things about Naruto's past or his true feelings that were hidden before, which could be a turning point in the story.
As the story progresses, his friends would likely start to worry and try to reach out to him. But Naruto, with his closed heart, would push them away. This could lead to some conflict among his friends as they argue about the best way to help him. Some might think they should give him space, while others want to force him to open up. In the meantime, Naruto's skills might start to deteriorate because his emotional state affects his ability to use his chakra effectively. And this could put the village in danger if there are threats around. Eventually, through some big event, like a major attack on the village where Naruto realizes he needs his friends and the power of their bonds, he may start to open his heart again.
Perhaps after facing too much betrayal from the village he loves. If the villagers turned on him despite all his efforts to protect them, it might lead him to close his heart in self - defense, not wanting to be hurt again. He's always tried so hard to gain their acceptance and if that was all for naught, it would be a huge blow.
It could also be due to the constant pressure and expectations on him. He's always had to be the hero, the one to save the village. If he feels he's constantly failing or not living up to those expectations, he may close his heart to protect himself from that self - doubt and disappointment. In the fanfic, perhaps there are new threats to the village that he feels he can't handle, and this leads to him shutting down emotionally.
Self - reflection is key. If Naruto takes the time to really look at himself and understand why he closed his heart in the first place, he can start to work through those issues. Maybe he realizes that closing his heart is only causing him more pain in the long run and that by being open, he can experience the full range of human emotions again, both the good and the bad.
The story could take a dark turn. Without his heart, Naruto might become a soulless being, and his friends would be devastated. They might try to find a way to get his heart back. Maybe they search for a powerful sage or some ancient magic that could reverse what has been done.
I recommend " Happiness on the Left " and " Contracted Boyfriend is the President " to you. " Happiness on the Left " was about a beautiful and cold girl who sealed her emotions in order to forget the pain of the past, until she met a man who closed his heart. " Contracted Boyfriend is the President " was about the male protagonist, Gu Han, who had learned to shut himself off due to the mysterious death of his parents. It was not until the appearance of the female protagonist, Xia Lewei, that his heart changed. Both novels described the protagonist's experience of emotional trauma and sealing off his emotions. I hope you like these recommendations!
A 'demon in his heart' in a Naruto fanfic could refer to many things. It might be about a character who has an inner struggle with a 'demon' - perhaps a dark side of their nature, like Naruto's struggle with the Nine - Tails. It could also be about a new character introduced in the fanfic who has a 'demon' within them that affects their actions and relationships with other characters in the Naruto universe.
I'm not entirely sure as I haven't read this specific fanfic. But from the title, it might be about Naruto feeling neglected and then something related to his heart and perhaps his growth or a big event that changes things. It could be a story that delves into the emotional side of Naruto that is often overlooked in the original series.
It might have a darker or more intense plot. Maybe the characters' emotions and motivations are explored in a deeper and more complex way.
A cold heart Naruto fanfic can be compelling if it has a unique plot twist or shows a side of Naruto we don't usually see.
I'm not sure specifically as it's a fanfic. It could be about a ninja in the Naruto universe with some sort of connection to an 'ashikabi' and the concept of 'heart'. Maybe it's a story that delves into a character's emotional journey within the Naruto - inspired world, perhaps with new powers or relationships related to this 'ashikabi' idea.