Definitely Orihime. She is the type who would be easily attracted to Goku's pure - heartedness and his determination to protect. Her own insecurities might be soothed by Goku's confidence. Rukia, with her sense of duty, could find herself drawn to Goku's selfless acts of heroism. And Neliel could also be part of the harem. Her child - like form and yet powerful true form would create an interesting relationship with Goku, as he might be protective of her in her child form and respect her power in her true form.
One idea could be a story where Goku is transported to the Bleach universe and somehow ends up attracting a harem of female characters from Bleach. For example, Orihime could be intrigued by Goku's incredible strength and kind heart, and gradually develop feelings for him. Another could be that Goku saves Rukia from a powerful enemy in the Bleach world, and as a result, she and other female Soul Reapers start to follow Goku around, leading to a harem - like situation.
Rebecca could potentially be in Luffy's harem. After Luffy helped her in Dressrosa, she might develop feelings for him. She is a strong - willed and kind - hearted character. Another could be Shirahoshi. Luffy has a special connection with her as he saved her from being captured. Her gentle and innocent nature would contrast with some of the other more assertive members of the harem.
Well, Mirajane could be part of the harem. She has a motherly side and would want to comfort Natsu if he was betrayed. Levy is also smart and resourceful, and she could use her skills to help Natsu out. Juvia, with her obsessive love for Gray, might transfer some of that intense loyalty to Natsu if she saw him in a desperate situation after being betrayed.
Another theme is the exploration of different cultures. Since Naruto and Bleach have their own unique cultures, the fanfic often delves into how these cultures interact when the characters are brought together. This can include things like how the ninja way from Naruto might be perceived by the Soul Reapers in Bleach, and how the hierarchies in both worlds are navigated in the context of the harem relationships.
Tuxedo Mask could also be in the harem. He has a long - standing relationship with Usagi, and in a harem scenario, his feelings for her could be even more intense, competing with others for her love.
A powerful demon from another dimension could be the main villain. This demon could be seeking to destroy all Saiyans and starts targeting Goku, Caulifla, and Kale. He has unique powers that they have never faced before, like the ability to nullify their energy attacks.
In addition to the obvious ones like Sakura and Hinata, Ino could also be part of the 'naruto x yugito harem'. Ino has always been competitive with Sakura over Sasuke, but in this fanfiction scenario, she might see Naruto in a new light and be drawn to him. Tsunade could also be an interesting addition. She is a powerful and experienced ninja, and her relationship with Naruto as his mentor could potentially take on a different, more romantic - ish turn in the context of a harem fanfiction.
Well, 'The Harem of Ichigo in Bleach' is also a great one. It delves into how Ichigo deals with the different personalities in his harem. Each character in the harem has their own backstory and motives, which makes the story complex and interesting. There are also some really cool action scenes that are intertwined with the relationship building.
In a crossover with Sailor Moon, Sailor Venus could be part of the harem. She is a strong fighter like Goku in her own way, and their different powers and personalities could create interesting dynamics.
Lois Lane could be one of the characters. She has a long - standing relationship with Superman in the original lore, so she could be part of the harem. Then there could be other female superheroes like Wonder Woman. Her strength and noble character could make for an interesting dynamic with Superman in a harem setting. Also, Lana Lang from Superman's past could be included.