A plot could be that Eriko is a descendant of a powerful but long - forgotten clan. Naruto discovers her during one of his missions. She has no idea about her heritage. Naruto decides to help her find out more. Along the way, they face enemies who want to stop them from uncovering the secrets of Eriko's clan. They must use their combined skills, Naruto's ninjutsu and Eriko's emerging powers, to defeat the enemies and unlock the truth about her clan.
In a Naruto and Eriko fanfic, Eriko could be a foreign exchange student in Konoha. Naruto is assigned to show her around. At first, they have some misunderstandings because of their different cultures. But as they spend more time together, they discover they both have a passion for helping others. They team up to help the villagers during a difficult time, like when a mysterious illness spreads. Their friendship deepens as they work hard to find a cure and protect the village.
Well, it could be about Naruto somehow being transported to the world where Dimentio exists. Maybe Naruto's ninja skills would be a novelty there and he'd have to team up with Dimentio to face some common enemy. They'd learn from each other's abilities, like Naruto teaching Dimentio about chakra and Dimentio showing Naruto some unique magic tricks.
One possible plot for a 'naruto bankai fanfic' is that there is a prophecy in the Naruto world that a power from another realm will be the key to saving it from destruction. Naruto is chosen to seek out this power. He discovers the concept of Bankai in the Bleach realm. After many trials and training sessions with some friendly Shinigami, he unlocks his own version of Bankai, which combines his chakra and the spiritual energy of Bankai. With this new power, he unites the villages like never before as they face a common, extremely powerful enemy.
Perhaps the plot could start with Orochimaru experimenting with some strange new chakra that is actually the Venom symbiote. Naruto gets infected during a battle with Orochimaru's minions. With the Venom symbiote, Naruto has enhanced strength, speed, and a new form of stealth. But the symbiote also has a mind of its own and tries to make Naruto more aggressive. Naruto has to fight against this internal struggle while also facing external threats from enemies who want to use the symbiote for their own evil purposes.
The plot could involve a Naruto character, say Naruto himself, being chosen by a Valkyrie for a special mission in a different realm. This would take him out of his comfort zone in the Hidden Leaf Village. Along the way, he would learn about the Valkyrie's culture and powers, and they would combine their strengths to overcome various challenges and foes.
The plot could start with Naruto finding a strange magical object during one of his missions. This object could be related to the powers of Shazam. Once he touches it, he is suddenly transformed and gains Shazam's powers. He then has to figure out how to use these new powers while still being a ninja. He might face enemies who are after his new powers, and he has to protect his village from them.
Perhaps Naruto discovers some ancient power or prophecy that makes him the rightful emperor. He then has to deal with the political intrigue within the ninja world. Some might oppose his rule, thinking he's too young or inexperienced, while others see him as the savior. He'd have to build his court, choose his advisors, and face external threats from other lands that see a united ninja world as a threat.
The plot of 'naruto and the 100 crossover fanfic' might center around a strange anomaly that transports Naruto to the universe of 'The 100'. Once there, he meets Clarke and the others. He starts to teach them some of his ninja techniques, like how to move stealthily or use chakra to enhance their physical abilities. In return, they teach him about their world's technology and survival skills. This exchange of skills could be crucial in their fight against the various factions vying for power in 'The 100' world.
One possible plot could be that Naruto discovers he has Senju blood through some hidden family secret. He then has to deal with the implications of this new identity while still trying to achieve his goal of becoming Hokage.
Maybe Naruto gets cursed during a mission, and the curse makes him see apparitions of his worst fears. These apparitions haunt him everywhere he goes. For example, he might see the ghosts of his fallen comrades or the villains he thought he had defeated, and he has to find a way to break the curse.