It might be a local event organizer in a town where the Backstreet Boys are having a Christmas concert. This person has to deal with all the chaos of organizing the event during the busy Christmas season, while also getting to know the Boys on a more personal level.
It could be a die - hard fan. A girl who has always dreamed of meeting the Backstreet Boys on Christmas. She gets the chance when they do a surprise visit to her hometown for a Christmas event. She then becomes part of their day and has an amazing adventure with them.
Perhaps a young boy who is an orphan. The Backstreet Boys find him while they are doing some Christmas charity work. They take him under their wing for the holidays, and he becomes a central figure in the story as he experiences love and care from the Boys during Christmas.
Maybe it's a story where the Backstreet Boys meet some kids on Christmas Eve. These kids are big fans but are having a tough time. So, the Boys decide to make their Christmas special by taking them out for a day full of fun activities, like ice skating and having a big dinner together.
In these fanfictions, the music of the Backstreet Boys is a big part. They might be performing their classic hits at a Christmas show. Also, family is often important. You could see them spending time with their own families or even creating a big 'Backstreet Boys family' gathering for Christmas. And the magic of Christmas, like Santa Claus or Christmas wishes coming true, can also be incorporated into the story.
Ron could be a main character. He might be the first one to notice Hermione's new haircut. He could have a really strong reaction, like blushing because he suddenly finds her even more attractive with the new look. And their relationship could develop further because of this change in her appearance.
It could be Abuela Alma. Since Mirabel getting a gift would have a huge impact on the family, Abuela's reaction and her journey of accepting this new change in Mirabel could be a major part of the story.
Sasuke could be a great main character in such a fanfiction. He has a deep connection with Naruto. If Naruto's dying will flame is involved, Sasuke might be on a journey to understand what Naruto left behind and how to carry on his legacy. He could be conflicted between his own past and the new responsibility that comes with the dying will flame.
Well, I'm not sure of the exact titles, but a good Christmas - themed Backstreet Boys fanfiction would probably involve their music. For example, they could be writing a new Christmas song together. Or perhaps they are in a small town during Christmas and inspire the local community with their music. The stories often play on their charm and the holiday spirit to create an engaging read.
A theme that might show up is disappointment. The fan could be disappointed by something the Backstreet Boys did or didn't do in the fanfic. It could be a cancelled concert, or a member leaving the group unexpectedly. And there could also be the theme of heartbreak. If the fan has a relationship with a member in the fanfic and it ends badly, it would create a very sad story.
One highlight is their global popularity. They were known everywhere. Another is their iconic songs.
Obviously, the future son would be a main character. He could be a young boy full of curiosity and new ideas.
Commissioner Gordon would likely be a main character. He has been Batman's ally for a long time, and with Batman retiring, he'd have to face the challenges of keeping Gotham safe on his own. Also, Robin, if there is a current Robin in the story, could be a main character. He might be left with the big shoes to fill that Batman has left behind.