One interesting storyline could be about Naruto visiting Gaia and learning about its unique chakra or energy system. He might encounter beings there that are similar to those in the Naruto world but with their own distinct abilities.
In some Naruto x Gaia fanfiction, there could be a plot where Naruto has to team up with Gaia - inspired characters to stop a common enemy. For example, an evil force that is threatening both the Naruto universe and Gaia. This would involve a lot of character development as they learn to work together, with Naruto sharing his ninja skills and his new allies teaching him about Gaia's powers.
One interesting Naruto Gaia fanfiction could be those that explore alternate universes where Naruto has different powers or allies. For example, a story where Naruto befriends a powerful ancient spirit early on and uses that newfound connection to change the course of events in the Hidden Leaf Village.
One interesting storyline could be Naruto finding himself in the Final Fantasy VII world and teaming up with Tifa to fight a common enemy. Maybe they use Naruto's ninja skills and Tifa's martial arts to take on a powerful foe threatening both their worlds.
One interesting storyline could be about Kushina getting to see Naruto's growth as a ninja in a more personal way. For example, she might be able to witness his training sessions and offer her own unique insights based on her own experiences as a kunoichi.
In some Naruto x Eyeshield 21 fanfiction, there could be a plot where the ninjas compete against the Eyeshield 21 players in a modified version of football. The ninjas would use their unique abilities like shadow clones or chakra control to gain an edge. It would be a fun mix of two different worlds. Or perhaps there's a story where a character from Naruto has a doppelganger in the Eyeshield 21 universe and they switch places, leading to all sorts of comical and challenging situations as they try to adapt to the new environment.
One interesting storyline could be Naruto and Konan teaming up to face a new, powerful enemy that neither of their villages has encountered before. They have to combine their unique skills, like Naruto's Rasengan and Konan's paper techniques, to defeat the foe.
Another storyline could involve Ryukyu teaching Naruto some special techniques that are unique to her tribe or region. This could lead to Naruto developing new forms of his jutsu. For example, he could incorporate some of Ryukyu's elemental or spiritual knowledge into his Rasengan, creating a more powerful and diverse attack.
One interesting storyline could be Naruto and Yugito teaming up for a dangerous mission. They might have to face a powerful enemy that neither could defeat alone. Their combined skills, Naruto's Rasengan and Yugito's ability to transform into the Two - Tails, would make for an exciting battle sequence.
A really cool naruto x fuka fanfiction plot could be set in an alternate universe where Naruto is not from Konoha and Fuka is a princess of a small ninja village. Naruto arrives in her village seeking refuge and they end up teaming up to defend the village from a much larger and more powerful enemy. Their relationship develops as they fight side by side and learn about each other's cultures and dreams.
In some Naruto x Brave fanfiction, there could be a story where the Braves are summoned to the Naruto universe. They have to learn about chakra and ninjutsu while also using their own unique abilities. This creates a lot of comical and interesting situations as they adapt to this new world and interact with Naruto and his friends.
One interesting storyline could be Naruto using his ninja skills in the WWE ring. For example, he might use his shadow clone jutsu to confuse his opponents during a match. It would be really cool to see him create multiple clones and then perform different wrestling moves from different directions.