Another aspect of the plot could be that Naruto's sister has some special powers or knowledge that makes her think she's the only one who can protect Naruto. She could have a connection to an ancient ninja clan that has secrets about protecting the host of the Nine - Tails. As a result, she feels it's her duty to be by Naruto's side at all times, which causes Naruto to feel smothered and strive to break free from her overprotection.
The plot might also involve Naruto's sister getting into trouble herself while trying to protect Naruto. She could end up making enemies with other ninja clans or rogue ninjas who see her as a threat because of her interference in Naruto's life. This would then force Naruto to not only deal with his own problems but also to rescue his sister, leading to a growth in their relationship as Naruto realizes that her overprotection comes from a place of love.
The plot could start with Naruto's sister being introduced suddenly. Maybe she was away for a long time, and now she's back and realizes how much Naruto has grown up but also how much danger he's in as a ninja. She then starts to follow him around everywhere, much to Naruto's annoyance. For instance, she might show up during his battles and try to jump in to protect him even when he doesn't need it.
One possible scenario in this fanfiction could be that Naruto's sister constantly interferes in his ninja training. She might think the training is too dangerous for him and tries to stop him from taking on challenging missions. For example, when Naruto is about to go on a mission to the Land of Waves, his sister could try to convince the Hokage not to send him, believing that he's not ready yet. This would add a whole new layer of conflict to the story, not just between Naruto and his sister, but also with the village's expectations of Naruto as a ninja.
The plot could revolve around Kushina trying to keep Naruto away from any potential harm. For example, she might not allow him to go on certain missions or even just play in dangerous areas. This would create a conflict as Naruto has his own desires to prove himself and be a normal ninja.
There are quite a few out there. In a lot of these 'Naruto overprotective sister fanfiction' stories, the sister is usually a new character created by the author. Her overprotective behavior can stem from Naruto's status as a jinchuriki or simply because she loves him dearly. For instance, she might train secretly to be strong enough to protect him. These fanfictions can offer a different perspective on Naruto's growth and the relationships he forms within the Naruto universe.
In a 'naruto gets pregnant fanfiction', perhaps there is a powerful enemy who casts a spell on Naruto. This spell not only endangers his life but also has the side - effect of making him pregnant. The story could then revolve around Naruto trying to find a way to reverse this while also dealing with the reactions of his friends and the village.
The plot could revolve around Naruto being entered into a ninja beauty contest by Sakura as a joke. But Naruto, being Naruto, decides to take it seriously. So, he gets a total makeover. He starts training not just in combat but also in poise and grace. His makeover includes learning how to groom his hair better, wearing more refined ninja clothing, and even learning some basic etiquette. Along the way, he discovers a new side of himself and also manages to change some people's perception of him in the ninja world.
Well, it could be that Naruto discovers a hidden Pokemon in the Hidden Leaf Village. This Pokemon might have some special powers related to chakra. He then decides to train this Pokemon and enters Pokemon battles using his ninja strategies. He could also meet other Pokemon trainers who are interested in learning his ninja ways in exchange for Pokemon training tips.
One possible plot could be that Naruto discovers he has a hidden bloodline that gives him the ability to control time on a small scale. He has to learn to master this new power while keeping it a secret from his enemies. With this new bloodline, he could rewind a few seconds during battles to avoid attacks or foresee his opponents' moves.
In a fanfiction with such a title, it might be about Naruto coming across a character who is wrongly enslaved in a hidden part of the ninja world. Naruto, with his kind heart, decides to fight against the system that allows this slavery and in the process, the 'slave' character might end up being a great asset to Naruto in his future adventures, but not in an actual master - slave relationship but more of an equal partnership born out of mutual respect.
One possible plot could be that Naruto discovers a magical sword. This sword might have special powers like being able to cut through any jutsu. He then has to learn how to master it, which could involve going on a journey to find an old hermit who once used the sword. Along the way, he faces challenges from enemies who also want the sword for their own evil purposes.
Well, one possible plot could be Naruto struggling with the physical and mental toll of cancer while still trying to protect the village. He might have to rely more on his friends and family as his ninja abilities are hampered by his illness.