Often, Hinata might be included. Since Hinata has a long - standing relationship with Naruto in the original series, in a harem fanfiction, she could be part of the group. Also, Sakura could be there. She has her own complex relationship with Naruto in the original Naruto story, so it makes sense for her to be in a harem setting with him in fanfiction. Another character could be Ino. She is also a female ninja who has interacted with Naruto and could potentially be part of this harem scenario.
In the fanfiction, a big challenge could be the jealousy or interference from other characters. There might be other people who have feelings for Naruto or Hanabi. For Naruto, Sakura might still have some unresolved feelings, and she could potentially cause some problems for their relationship. For Hanabi, there could be members of the Hyuga clan who oppose her being with Naruto, thinking that he is not a suitable match for her in terms of clan traditions and politics. All these factors combined would create many challenges for Naruto and Hanabi to overcome.
It can be normal. Many fans like to engage with multiple aspects of a fandom simultaneously. Watching 'Bleach' and reading its fanfiction can be a way to satisfy different cravings for the story. For example, the fanfiction might explore character relationships in more depth or present alternate plotlines that can be really interesting to compare with the original series.
A crisis situation could also be used to develop their relationship. Suppose there is an attack on the village and they have to protect it together. They would need to rely on each other's skills. Boruto's innovative ninja techniques combined with Hanabi's precise and powerful Hyuga jutsu could be a great combination. This shared experience of defending their home would make their relationship stronger and more meaningful.
The Hyuga clan members would be very confused by 'Hanabi' (really Naruto). They would notice her (his) un - Hyuga - like behavior and attitude. For example, Naruto's loud and friendly nature would be a stark contrast to Hanabi's more reserved Hyuga self. As for Naruto's friends, they would be puzzled by 'Naruto' (actually Hanabi). They would wonder why he (she) seems a bit different in combat and decision - making.
For Hinata, her development could focus on her becoming more assertive. In the fanfic, she could start taking on leadership roles within the clan. With her relationship with Naruto, she could also gain more confidence. For Hanabi, her development could be about her learning to be more empathetic. She might start to understand the feelings of others more, especially her sister Hinata. This could be shown through their interactions, like when they have heart - to - heart conversations.
In this fanfiction, Naruto's personality could shift in a few ways. He'd likely become more attuned to the needs of the Hyuga clan, trying to fit in and understand their ways. His impulsiveness might be tempered a bit as he has to consider Hanabi's feelings and the traditions of her family. Hanabi would change too. She'd become more flexible, learning from Naruto's ability to adapt to different situations. Her quiet nature could gain a bit of Naruto's boldness, and she might be more willing to speak up for what she believes in, especially when it comes to their relationship.
It can enhance your understanding of the 'Bleach' universe. Fanfiction often delves deeper into character backstories and relationships. For instance, you might learn more about a side character's motives or a relationship between two main characters that was only hinted at in the show. Also, it can keep you engaged with the 'Bleach' fandom even when there's no new official content.
In my opinion, both have their merits. The anime brings the characters to life with animation and sound, but the manga allows for more imagination and detail in the panels. It really comes down to what you value more in your entertainment.