Hinata is a very likely candidate. She has always had strong feelings for Naruto and in a multi - marriage scenario, she could be one of the first to be considered. Sakura could also be a possibility. Despite her initial feelings for Sasuke, in fanfiction, the story could be rewritten so that she realizes her true feelings for Naruto and becomes one of his wives.
Another possibility is Sakura. Although she has feelings for Sasuke in the original, in this fanfiction, the story could be rewritten so that she realizes her true connection with Naruto and they end up getting married at 12. Their dynamic would be quite different from the original, with Naruto having to prove himself in a new way to Sakura.
One possible storyline could be Naruto marrying multiple characters from different clans, which would bring about unique cultural fusions within the Hidden Leaf Village. For example, if he marries a character from the Hyuga clan and another from the Inuzuka clan, there could be interesting interactions between the different family traditions and abilities.
It could be a long - lost heir to a powerful, almost forgotten dynasty who resurfaces. This heir, being royalty, might have some special powers or knowledge. And Naruto, being the hero he is, could be drawn to her because of her unique qualities and the potential she holds for bringing about positive change in the world.
Sakura could be a potential partner. Since they are friends from the original series, a forced marriage situation between them would bring a whole new dynamic. There would be a lot of room for exploring their relationship beyond just friendship.
From the Naruto universe itself, Hinata and Sakura are obvious choices. In a crossover, characters like Erza from Fairy Tail could be included. She is strong - willed and would make an interesting addition to Naruto's harem. Also, Nami from One Piece could be there. Her intelligence and navigational skills would add a different dynamic to the group.
One of the most common characters to crossover with Naruto is Saitama from One - Punch Man. Saitama's overpowered nature and Naruto's underdog - turned - hero story can make for some humorous and action - packed crossovers. Another popular character is Kirito from Sword Art Online. His skills in a virtual world can be compared and contrasted with Naruto's real - world ninja skills. And of course, there's also Alucard from Hellsing. His vampire powers and Naruto's ninja powers can lead to some very dark and intense crossovers.
Tsunade would definitely be one. As the most renowned medical ninja in the village, she could either be Naruto's mentor or a colleague. They could exchange medical knowledge and experiences.
In 'naruto as a cat fanfiction', Jiraiya could be an interesting character to interact with Naruto as a cat. He might see some potential in this cat - form Naruto for some new ninja techniques. The Akatsuki members could also interact with Naruto as a cat. For example, Itachi might sense something unusual about this cat when he passes through the village. And Konohamaru could be another character. He would be really excited to have a cool cat friend, not knowing it's Naruto.
Naruto might interact with Eostia's warriors. They could train together, Naruto showing them his ninja combat skills and them teaching him about Eostia - style combat. There could also be some mysterious characters in Eostia, like an old hermit who has some knowledge about Naruto's sudden appearance in their world and could guide him on his journey in Eostia.
It could be Sasuke's sister, if there was one in the fanfiction world. She might share some of Sasuke's traits but also have her own unique personality that attracts Naruto.