In a 'naruto x monster harem fanfiction', Naruto could be cursed by an evil sorcerer. The only way to break the curse is to gain the true love of several monster girls. So he embarks on a journey to understand and befriend these different monster species. He meets a dragon - girl who is initially fierce but softens towards him as he respects her strength, and a forest - nymph - like monster who heals his wounds and gradually falls in love with him.
One idea could be that Naruto discovers a hidden realm full of monster girls. They are initially wary of him but as he shows his kind heart and powerful ninja skills, they start to fall for him. For example, a fox - like monster girl might be drawn to his own connection with the nine - tailed fox.
Well, perhaps Naruto accidentally awakens an ancient power that has the side effect of creating a harem of monster girls. These monster girls could each have different abilities and personalities. For example, a fox - like monster girl could be very sly and intelligent, while a bear - like one could be strong and protective. They all vie for Naruto's attention in their own ways.
Another plot could be that there is a threat to both the Naruto world and Monster High. Naruto teams up with the Monster High crew, and during their adventures, some of the female characters start to develop feelings for him. He is constantly saving them with his Rasengan and other jutsu, and his kind heart makes them fall for him one by one, creating a harem.
One idea could be Naruto somehow finds himself in a situation where he has to team up with Tayuya frequently. As they interact more, a harem starts to form around Naruto, with Tayuya being one of the key members. The plot could involve them going on missions together and Naruto gradually realizing his feelings for Tayuya among the others in the harem.
One idea could be that the OC is a powerful ninja from a far - off land. She comes to Konoha and catches the attention of Naruto and his friends. As she gets to know them better, she forms unique bonds with each of them, leading to a harem - like situation. For example, she might train with Naruto and they share their dreams of becoming Hokage and protecting the village. With Sasuke, she could be someone who understands his pain and tries to bring him back to the light. And with others like Shikamaru, she might engage in strategic battles and discussions, slowly building relationships.
One idea could be that Naruto, with his unique charm and strength, gradually attracts Konan and other characters into his 'harem'. For example, they could go on adventures together, facing various threats in the Naruto universe, and during these experiences, their relationships deepen. Naruto could use his ninja skills to protect them, and they in turn offer different forms of support, like Konan using her paper abilities for strategic advantages.
One idea could be that Naruto is somehow transported to the Overlord world and his unique abilities draw the attention of various female characters, leading to a harem situation. Maybe his ninjutsu skills are seen as a form of magic there.
A possible plot could involve a competition among the members of Naruto's harem. Since they are all in love with Naruto in this genderbend scenario, they might compete in ninja tasks or challenges to prove their worth to Naruto. Maybe there could be a tournament where they show off their jutsu, and Naruto has to judge not only their skills but also how their actions affect their relationships with him.
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 that Naruto, after achieving great power, somehow travels back in time and meets Kaguya before she turned evil. He then forms a harem with her and some other female characters from the Naruto universe who are also drawn to his unique power and kind heart.
Another plot could be that Naruto is mistaken for an Avatar in the Avatar world. As he tries to clear up the misunderstanding, he gets involved in local politics and relationships. The female characters see his honesty and kindness, and gradually, a harem - like situation develops around him.