Romantically, if Hermione becomes a boy, she might attract different people. Maybe some of the female students who were just friends with her before start to have a crush on her. And she would have to figure out how to handle these new romantic interests while still being true to herself and her old friendships.
If Bella becomes a banshee, her relationship with Edward would be very different. He would be more protective of her as she has a new and potentially dangerous power. He might also be a bit wary as banshees are known for their wailing which could attract unwanted attention. With Jacob, he might see her as even more of an enigma and be more drawn to her in a way, since she's now a more powerful supernatural being.
With his son Gohan, the relationship could be strained. Gohan has always looked up to Goku as a hero. But as Kakarot, Goku might push Gohan to be more like a traditional Saiyan, which could be too much for Gohan. Also, Vegeta's view of Goku would change. Vegeta has always seen Goku as a rival but also respects him. As Kakarot, Vegeta might see him more as a threat to the Saiyan way of life or as a potential ally in a more Saiyan - centered agenda.
Her relationship with the Sakamaki brothers would become more complex. They might see her as both a threat and an equal now. Before, she was just a human for them to toy with, but as a vampire, she could challenge their dominance.
Hermione's relationship with Harry and Ron would likely become more strained. They might be a bit afraid of her at first, not knowing how to deal with her new lycanthropy. However, as true friends, they would eventually try to understand and support her. With other Hogwarts students, she could face discrimination or fear from some, while others might be curious or sympathetic. Her relationship with teachers would also be different. Some, like Professor Snape, might use it as an excuse to be even harsher on her, while others, like Professor Lupin (who is also a werewolf), could be a source of guidance.
Her relationship with her adoptive parents might become a bit strained at first. She could start to question their motives for not telling her. But over time, she might come to understand their reasons and their love for her remains the same.
His relationship with Sasuke would be really interesting. Since Sasuke has his own complex connection to the Uchiha clan and Madara, Naruto becoming a Madara fan could either bring them closer together in understanding the Uchiha's past or drive them further apart if Sasuke doesn't agree with Naruto's new - found admiration. Maybe Naruto would start to push Sasuke towards a more 'Madara - like' view of power and revenge.
His relationship with Sakura would change a lot. Sakura might be initially scared of Naruto's fox form, but as she realizes it's still him inside, she would start to see him in a new light. She could become more protective of him. With Kakashi, Kakashi would be more cautious and observant, trying to figure out how to help Naruto control his new form. And with his rivals, they might either be more envious or more afraid of him now that he has this unique transformation.
His relationship with Sasuke would be very different. Sasuke might see Naruto as even more of an enigma. He could be both jealous of Naruto's new power and also concerned about what Naruto has become. Naruto, on the other hand, would try to show Sasuke that he's still the same person deep down.
Naruto's relationship with the villagers could be affected. As he becomes a Minato fan, he would try to uphold Minato's legacy even more. The villagers, seeing Naruto's newfound admiration for Minato, might start to see Naruto in a new light, more like how they saw Minato. Also, his relationship with Hinata could be different. Naruto might start to model his family - centered values after Minato, which could bring him and Hinata even closer as they plan their own family.
Bulma's relationship with the other Z - fighters would also be different. They would no longer see her as just the tech - support person. Now, she could be a front - line fighter. They might be in awe of her new powers at first, but then they would start to rely on her more in battles, and she would have to learn how to work with them in a more combat - oriented way.