He might possess a stealth device. This would allow him to move around undetected, which would be very useful for surprise attacks. He could also have a device that can disrupt enemy jutsus, making it difficult for his opponents to use their ninja techniques effectively.
He could have a laser - sword like in some sci - fi stories. It would be a cool addition to his arsenal. He could use it for close - range combat, slicing through enemies and defenses with ease.
Maybe Naruto is sent on a special mission to a foreign land where high - tech weaponry is common. He secretly gets his hands on some of these weapons, like a wrist - mounted energy blaster. He uses it sparingly in battles back in Konoha to protect his village without revealing his new arsenal. The story could revolve around him trying to keep it a secret while also learning how to fully utilize these high - tech weapons.
Sasuke would be suspicious at first. He might think Naruto is getting power from a dangerous or untrustworthy source. But once he sees Naruto using the high - tech weaponry for the good of the village, he would start to accept it. Sakura would be worried about Naruto getting in over his head with these new and unknown weapons. She would constantly be checking on him to make sure he's not endangering himself. Kakashi, on the other hand, would be intrigued. He would want to study the weaponry and see how it could be integrated into Konoha's defenses.
Well, it could make his combat style more unpredictable. Instead of relying solely on his ninja skills like shadow clones and rasengan, he can now use high - tech gadgets. For example, he might have some sort of energy - based weapon that can stun enemies from a distance. This would add a new dimension to his fighting, allowing him to keep opponents at bay while he plans his next move with his traditional ninja techniques.
High tech can greatly shift the power dynamics. For instance, if a ninja has access to a high - tech armor that can nullify most attacks, they become a formidable force. Others would have to find new ways to defeat them.
One interesting idea could be high - tech ninja tools. For example, shurikens with built - in tracking devices. This would add a new dimension to the battles in the Naruto universe. It would make the fights more strategic as ninjas could track the movement of their opponents' weapons.
Perhaps the fanfiction could start with Saeko finding an unconscious Naruto in the middle of the chaos. As he wakes up, he has to quickly adapt to this new world. They decide to head towards a rumored safe haven. Along the journey, they face not only zombies but also other survivors who turn out to be more of a threat. Naruto's ninjutsu and Saeko's combat skills are put to the test. As they get closer to the safe haven, they uncover a conspiracy behind the zombie outbreak, and they must decide whether to expose it or just focus on survival for themselves and the group they have gathered along the way.
There could be a storyline where Naruto is summoned to the High School DxD world by some ancient magic. He is seen as a powerful ally or a threat depending on who you ask. Rias takes it upon herself to figure out Naruto's intentions. As she gets to know him, she realizes that his values of friendship and protecting the weak are similar to her own. Together, they start a journey to stop a dark force that is rising in the DxD world, with Naruto teaching the devils some ninja techniques along the way.
Well, they could be involved in a school sports competition. Naruto would be all about the spirit of the game, while the Female Kyuubi might initially be reluctant but then get really into it to prove her strength. Or perhaps they are in a club together, like a mystery - solving club. They would use their unique skills, Naruto's ninja skills and the Kyuubi's intuition, to solve various strange events that happen around the school.
One possibility could be that Naruto has been poisoned by a new and unknown enemy. This poison is slowly eating away at his life force, and he's trying to hide it from his friends and family so as not to worry them. He might be secretly seeking a cure while still fulfilling his duties as Hokage.
If Naruto secretly sings fanfiction, it could lead to some interesting scenarios. For one, if his friends were to find out, they might be really surprised. It could also potentially get him into trouble if the content of the fanfiction he's singing is inappropriate or goes against the values of the ninja world. But on the positive side, it could inspire others in the village to explore their creative sides as well.