In a Naruto succubus crossover fanfiction, a succubus could be an outcast in her own realm and seek refuge in the Naruto world. She disguises herself as a normal human and tries to live a peaceful life. But her past catches up with her, and Naruto and his team end up having to protect her from the other demons that are after her.
Maybe a group of succubi are summoned accidentally in the Naruto universe. They cause chaos as they are used to a different kind of world. Naruto and his friends have to figure out how to send them back without harming them, while also dealing with the succubi's alluring powers that are affecting some of the villagers.
One idea could be a forbidden love story where a human falls in love with a succubus. The succubus is initially only interested in his energy but gradually develops real feelings. Another could be a story set in a magical academy where a succubus uses her kiss to gain an advantage in a competition, but then finds herself falling for one of her rivals.
A plot could be that a succubus is sent to the Naruto universe as part of a deal between dark forces. She targets Naruto because of his growing power. But as she gets closer to him, she starts to feel real emotions for him instead of just using him for power. This creates a conflict within her as she has to choose between her original mission and her new - found feelings.
A plot could also be where Naruto is wrongly accused of being a succubus - like being a danger to the village because of some strange powers he has. Kushina, even though she has passed away, appears to Naruto in his mind or as a spirit guide. She gives him the strength and wisdom to prove his innocence and show that his powers can be used for good, rather than being seen as something evil like a succubus.
One interesting plot idea could be a crossover where Naruto's senjutsu abilities are combined with another universe's magic system. For example, if he were to cross over into the Harry Potter universe, he could use senjutsu to enhance his magic or even teach the wizards about chakra. Another idea is a crossover with the Dragon Ball universe, where Naruto's senjutsu clashes with the ki energy of the Saiyans. Maybe he has to use senjutsu to face off against a powerful Saiyan who has come to the Naruto world. Or a crossover with the Bleach universe, and Naruto uses senjutsu to interact with the spiritual energy there, perhaps even helping Ichigo in a battle against a powerful Hollow by using his unique senjutsu skills.
One plot idea could be that Naruto characters end up in Ikebukuro. For example, Naruto himself could be searching for a new type of ninja tool that he heard can only be found in Ikebukuro. Meanwhile, the gangs in Durarara start to notice this strange, orange - clad boy with strange powers. Another idea is a character swap where some of the Durarara characters gain ninja abilities and get involved in Naruto - style battles in their own world. Maybe Celty could use her shadow powers in a more ninja - like way, like stealth and quick attacks.
One idea could be that Naruto characters are transported into the Splatoon world. They might initially be confused by the ink-based battles and the unique species. For example, Naruto could mistake an Inkling for a strange ninja from another land and challenge them to a friendly spar, only to find out about the ink shooting mechanism. Another plot could involve the Akatsuki from Naruto trying to steal the valuable ink resources in the Splatoon world for their own purposes. They would face off against the Splatoon heroes who are determined to protect their world's resources.
A cool plot could be that there's a tournament across different anime worlds, and Inuyasha and Naruto are chosen to represent their respective worlds. Along the way, they discover similarities in their pasts, like both having some form of demon - related heritage (Naruto with the Nine - Tails and Inuyasha being a half - demon). They also exchange combat techniques. Naruto teaches Inuyasha how to better use chakra control in his attacks, and Inuyasha shows Naruto some unique sword - fighting skills.
One interesting plot idea could be that Kaguya is reborn in the modern Naruto world. She has no memories of her past at first. Naruto discovers her and senses a strange power within her. As she starts to regain her memories, she struggles between her old self and the new world she's in. Naruto has to decide whether to trust her or not.
Perhaps the nine - tailed fox in Naruto and the Avatar state could have some sort of connection. In the fanfiction, the two powers could interact in unexpected ways. For example, when Naruto enters his nine - tailed fox mode, Aang's Avatar state could be affected, or vice versa. They might have to learn to control these interactions to save both their worlds from a dark force that wants to use this power connection for evil.
One idea could be that Naruto gets a gamer power that allows him to level up his ninja skills like in a game. For example, he can see his progress in learning new jutsus as leveling up. Another could be a crossover with a popular game world where Naruto has to fight game bosses using his ninja abilities.