Perhaps there's a plot where an old enemy resurfaces and targets both Naruto and Sister Lemon. They have to put aside any differences or misunderstandings they might have had and work together to defeat this common foe. Along the way, they might also learn more about each other's pasts and secrets, which deepens their relationship.
A possible plot could be that Lemon is an artist who can paint the future. Naruto discovers her ability when he stumbles upon her in the forest. They start working together, with Naruto using her paintings to prevent disasters. However, there are some in the village who think Lemon's power is a curse and they try to drive her out. Naruto has to convince everyone that she is an asset to the village.
Well, a plot could involve a magical lemon that gives Naruto and Hinata the ability to see into each other's dreams. In these dreams, they explore their relationship deeper and face their insecurities. Or perhaps there's a lemon - eating competition in the village, and Naruto and Hinata team up. Through the chaos of the competition, they grow closer and realize their love for each other. It could also be that a lemon - scented perfume Hinata wears drives Naruto wild with attraction and he finally makes a move.
One plot idea could be that Fem Kiba discovers a new jutsu that only Naruto can help her perfect. They go on a journey together to different hidden villages in search of the knowledge and ingredients needed for the jutsu. Along the way, they face various enemies and make new friends. Another idea is that they are both chosen for a special mission that requires them to pretend to be a couple. As they pretend, they start to understand each other on a deeper level and form a real bond.
One idea could be a story where Naruto discovers he has a long - lost sister who has unique powers. They then team up to face a new and powerful enemy in the ninja world. Another could be a plot where the sister is from a different village and they have to overcome the differences between their villages to be together as family.
One idea could be a crossover where Naruto's world and the world of X - 23 from the X - Men collide. Maybe X - 23 is on a mission and accidentally ends up in the Hidden Leaf Village. She has to learn to adapt to this new place with its different culture and ninja ways. Naruto could be intrigued by her and her abilities, and they could team up to face a common enemy.
Well, a really interesting plot could be that Hidan gets amnesia and Naruto finds him. Naruto decides to help Hidan regain his memories, but as he does, he also tries to show Hidan a different way of life. Maybe Hidan starts to question his old beliefs. Also, a plot where they are both sent back in time and have to work together to prevent a great disaster in the Naruto world's past could be really cool.
Well, a plot could revolve around a prophecy that involves both Naruto and Ahsoka. They are initially unaware of each other but start having strange dreams that lead them to meet. Once they meet, they realize that they are fated to work together to bring balance to a new kind of energy that is affecting both their universes. Along the way, they form a strong bond of friendship and respect, and they also have to face challenges from their own respective sides. Some people in the Hidden Leaf might be skeptical of Ahsoka, and some in the Jedi order might be wary of Naruto's unorthodox ways.
Maybe Naruto's sister has a special ability that is enhanced by the Rinnegan. They get involved in a conflict against an ancient evil, and their combined powers are the only hope. The fanfiction could explore how they learn to work together, with Naruto protecting his sister while she unlocks new powers.
Another plot could be that Naruto's sister is in a harem - like situation where multiple guys are interested in her, but Naruto accidentally gets involved and ends up being the one the girls in the group are more attracted to. He might initially be oblivious to their feelings, thinking they are just being friendly because of his sister, but as time goes on, he realizes the true nature of their affections.
One idea could be Naruto being transported into the League of Legends world and having to team up with a champion to face a common enemy. Maybe he uses his ninja skills in unexpected ways in the battles. Another could be a crossover where Naruto's friends from Konoha also get involved in the LoL universe and they all have to adapt to the new environment.