The development of their relationship would be a bumpy road. There would be many misunderstandings at the beginning. Inuyasha's son might misinterpret some of Naraku's daughter's actions as being evil - inspired. But as they are forced to work together, they begin to understand each other better. For instance, when they are trapped in a dangerous situation and have to rely on each other to survive. This would break down the barriers between them and lead to a deeper connection.
Their relationship could develop through acts of kindness. Maybe Naraku's daughter saves Inuyasha's son from a dangerous demon. This would make him see her in a new light. And she, on the other hand, might be attracted to his sense of justice and honor, which is very different from her father. As time goes on, they would start to communicate more deeply, sharing their hopes and fears, and slowly falling in love despite the odds.
The plot could involve them being brought together by some sort of magical force. Maybe a powerful artifact needs to be protected, and they are the only ones who can do it because of their unique bloodlines. As they spend time together, they start to fall in love. However, they face a lot of opposition from both sides. The friends of Inuyasha's son think he's betraying his father's memory, and Naraku's old minions might try to use the daughter for their own evil plans.
He might also become more patient. Usually a bit hot - headed, but with Kagome pregnant, he'd have to learn to be more calm and understanding. For example, when Kagome has mood swings due to hormonal changes, Inuyasha would have to control his temper and be more supportive instead of getting frustrated.
You can start by giving them a common goal. For instance, if there's a threat to the world of feudal Japan that only they can stop together. This would force them to interact and gradually build some sort of understanding.
Inuyasha would also be worried about Kagome's safety. He knows how devious Naraku can be. He might call out to Kagome as he gets closer to Naraku's lair, hoping to hear her voice and know that she's still alive. His reaction would be a mix of anger, worry, and determination to rescue the woman he loves.
At first, their relationship could be rocky. Beetlejuice is a chaotic character, and the daughter might be a bit wary of him. But as time goes on, they could start to understand each other better. Maybe she sees the good in him that others don't.
Bella would likely develop a sense of identity based on her relation to Joshua. She might start to take on some of his traits, either positive or negative. For instance, if Joshua was known for his bravery, Bella could find herself being more courageous in difficult situations.
At first, Naruto might be a bit awkward around Jiraiya's daughter, given his respect for Jiraiya. But Tsunade, with her no - nonsense attitude, would push them to interact more. As they go on missions together, Naruto would see the daughter's determination and courage. This would make him open up more to her. He would start sharing his own stories and dreams with her. In turn, she would look up to Naruto even more, and their relationship would gradually evolve into a strong friendship or even something more in the long run.
For Red Leader, you could show his background that led him to be who he is. Maybe he had a tough upbringing which made him so power - hungry. As for the Queen's daughter, her character could be developed by showing her relationship with her mother. Is she trying to break free? This would influence how she interacts with Red Leader.
One idea could be a scenario where Inuyasha and Naraku are forced to team up against a greater evil. Maybe a powerful demon from another realm arrives and threatens to destroy everything they both hold dear. They start off distrusting each other but gradually learn to work together as they realize they have no other choice.
Naruto might become more of an isolationist. Danzo was not one to form close bonds easily. So Naruto could be more reserved and keep to himself. However, his natural urge for connection might still be there, and he'd struggle between his upbringing and his true nature. He could start off as a loner but gradually learn to open up as he experiences different things in the village and realizes that not all relationships are like the ones Danzo had.