Perhaps Lemon gets kidnapped because she has some sort of secret knowledge or power. Naruto then goes on a mission to rescue her, facing many challenges and enemies along the way. This could involve Naruto using his new - found Sage Mode or other advanced techniques to save his sister. Another plotline could be that Lemon is ostracized in the village because she's different, and Naruto has to fight to get the villagers to accept her, just like he had to earn their respect himself.
One possible plotline could be that Lemon has some unique ninja abilities that Naruto discovers, and they train together to become stronger. Maybe she has a special chakra nature that Naruto has never seen before, and they figure out how to use it in combat.
One plotline could be that Lemon discovers a hidden power within herself that is related to an ancient Uzumaki clan secret. As she tries to master this power, she has to keep it a secret from the wrong people in the village who might misuse it. Along the way, she gets help from unexpected allies like Shikamaru, who uses his intelligence to guide her in understanding the power better.
One plotline could be that his sister is being controlled by an enemy. Naruto has to fight her to break the control. He uses his Nine - Tails chakra to overpower her and then uses his talk - no - jutsu to bring her back to her senses, thus defeating her in a sense.
Perhaps she has a special connection to an ancient and powerful ninja art. This could lead to her being targeted by some villains who want to use her for their own gain. Naruto then has to step up to protect his sister, and in the process, they both learn more about their family's past and their own powers.
Well, one possible plotline could be that Ayane, for some reason, enters Naruto's world. Maybe she's on a mission or has been transported there accidentally. And then, through a series of events, they start to develop feelings for each other that lead to the more 'lemon' - ish aspects of the story. However, this would require a lot of world - building to combine their two different universes.
Perhaps in a 'naruto and elf lemon fanfiction', the elf has a special power that the Naruto world needs to defeat a new and powerful enemy. Naruto and the elf team up, and during their adventures, they start to develop feelings for each other. Their relationship could progress from friendship to something more, with some tender and a few more suggestive scenes as they get closer, like a shared moment under a starry sky where their relationship takes a new turn.
A plotline could involve an alien being stranded in the Naruto world. Naruto, being the kind - hearted hero, decides to help the alien. Along the way, they discover that the alien has some knowledge or power that is related to the 'Lemon' concept, which could be a mysterious energy source. This energy source might have the potential to either save or destroy the Naruto world, and they have to figure out what to do with it. As they work together, they also learn about each other's cultures and grow as characters.
Since 'lemon' often implies adult - themed content, I can't really provide detailed plotlines for that. But if we consider a general Naruto and Annabeth crossover without the 'lemon' aspect, a possible plotline could be them teaming up to face a common enemy that threatens both their worlds. Maybe they start off as rivals, not understanding each other's powers and ways, but gradually learn to work together.
One possible plot could be that Lemon, Naruto's sister, discovers some hidden jutsu that Kushina once knew. Naruto and Lemon then train together to master it. Along the way, they face challenges like other ninja clans trying to stop them as they fear the power of this new - found jutsu. And in the end, they use the jutsu to protect their village and honor Kushina's memory.
Perhaps there could be a plot where Naruto's twin sister gets into some kind of trouble, like being kidnapped by an enemy ninja clan. Naruto then goes on a desperate mission to rescue her. During this time, he realizes just how much she means to him. He uses all his skills and the power of his friends to get her back, and in the end, their bond becomes even stronger.
One possible plotline could be that Naruto's family is in a difficult situation and they believe they can only support his sister. So, Naruto is left on his own. He then has to struggle to survive in the ninja world without the support of his family. He might become more independent and self - reliant, forging his own path.