One idea could be to focus on the different relationships Naruto forms with the female characters in unique settings. For example, having Naruto go on a special mission with a group of girls from different villages, and during that mission, they start to develop deeper feelings for him. Maybe there could be a plot where they have to work together to solve a mystery that is related to all their villages.
Begin by creating a unique scenario for Naruto. Maybe he gets sent to a different dimension where the rules of the Naruto world are a bit different, and there he meets a group of female characters. Outline the personalities of these characters and how they will be attracted to Naruto. You also need to consider Naruto's own growth in this new situation. Will he become more confident? Or will he be more confused by all the attention? Write down some key events that will drive the story forward, like a big tournament where Naruto has to prove himself in front of his new friends and potential love interests.
Well, perhaps Naruto is sent to the Halo universe to stop a new threat that is affecting both his world and the Halo world. In this process, he meets female characters from different factions in Halo. His kind heart and powerful ninja skills make him a fascinating figure to them, and a harem starts to form around him. Some female Elites or human female soldiers might start to follow him, thinking he can lead them to victory against the common enemy.
In this type of fanfiction, there might be new settings. Picture an elven forest that is somehow connected to the Hidden Leaf Village. The elves could be protectors of a powerful chakra - infused artifact in the forest. As for the harem part, Naruto's interactions with the elf women could range from friendly and platonic to more romantic, with each relationship developing at its own pace and bringing out different sides of Naruto.
One idea could be that Naruto, with his ninja skills, gets transported to Starfire's universe. There, his unique abilities draw the attention of many characters, leading to the formation of an accidental harem. For example, his ability to make shadow clones might be seen as a very useful and cool power. Another plot could involve a common enemy that forces Naruto and Starfire, along with other characters who are part of the harem, to work together. This could lead to some interesting dynamics as they all come from different backgrounds and have different ways of fighting.
One idea could be that a Saiyan character somehow ends up in the Naruto universe and due to their unique powers, attracts a harem. For example, they might save a group of ninja from a powerful enemy using their super strength and speed, and the ninja, both male and female, become intrigued by this new and powerful being.
One idea could be that Naruto and Deadpool end up in a strange multiverse situation where they meet various female characters from their respective universes. They then have to team up to protect these females from a common enemy, and in the process, a harem - like dynamic forms as the female characters develop feelings for them.
The OC could be a descendant of a powerful clan that was thought to be extinct. Their presence in the Naruto world stirs up interest among many characters. The OC's knowledge of ancient jutsu and their kind heart draw in characters like Kakashi, Shikamaru, etc. into a harem. The OC then has to navigate the complex relationships while also trying to keep their clan's secrets safe.
Well, a plot could be that Naruto is a transfer student in a high - school that has a special ninja training program. The girls in the harem are all in different levels of the training. Hinata, being the shy one, tries to impress Naruto during training sessions. Ino, on the other hand, is more competitive and sees Naruto as a rival at first but then realizes her feelings. And Tenten could be the girl who helps Naruto with his weapon - based ninja skills in the high - school setting. They all end up in a harem - like situation around Naruto as he shows his growth and determination in the ninja high - school.
Maybe the island has some sort of magic that makes the women on it more attracted to Naruto. For example, it could be a chakra - related magic. As Naruto tries to figure out how to leave the island, he has to deal with the complex relationships that are developing among him and the female characters, like Sakura, Hinata, and Ino.
One plot idea could be that Naruto somehow gets transported to the world of Arrancars. He then starts to form relationships with different Arrancar characters, leading to a harem situation. Maybe he uses his ninja skills to protect them from other threats in their world, and in the process, they all fall for him.