Such a description might be used to make the character stand out in a fanfiction. He could be a unique character in a fantasy - based fanfic too. For example, he could be a wizard who has adapted to some modern - day human habits like wearing a hair tie on his wrist. His bun could be a way to keep his long hair out of his face while he's performing magic.
He can be mysterious. His unkempt hair in a bun makes him seem like he has secrets. In some fanfictions, he'll be the quiet type in the corner of a room, observing everyone, and his messy bun is part of what draws the other characters (and the readers) to want to know more about him.
There are many fanfiction platforms out there, but it might be a bit difficult to specifically find ones with this exact description. You could start by looking at platforms like Archive of Our Own (AO3). Try searching for tags like 'Male with hair tie' and 'Hair in bun' along with the fandom you're interested in. For example, if it's a Harry Potter fanfic, add 'Harry Potter' to the search terms.
The fact that her hair is in a bun might also play a role. It could be a cultural or traditional style in the fictional world she belongs to. When she's kidnapped, her captors might be disrespectful of this style, which angers her and gives her the motivation to resist. The bun could also be used practically during her captivity. For example, she might hide small objects in it to help her escape, like a lock pick or a small note.
You could also try Wattpad. There are a lot of independent authors on there who might create unique fanfictions with this character description. The man with a messy bun could be a modern - day character in a contemporary fanfiction, perhaps an artist or a musician. His messy bun could symbolize his free - spirited nature and creativity, and the story could revolve around his journey in the art or music world.
One idea could be that Felicity is kidnapped by a rival of her friend. Her hair in a bun might be a key detail, like the kidnapper uses it to hold her captive in some way, perhaps by tying her bun to a post. Then her friends have to figure out where she is based on the few clues she manages to leave behind, which are related to her bun.
A girl at the waterpark with her hair in a bun could be the start of a really interesting fanfiction. She could be a shy girl who usually keeps to herself. But at the waterpark, something changes. She sees a group of people playing a really fun water game and decides to join in. As she plays, her bun starts to come loose, which adds a bit of humor to the story. And through this experience, she gains more confidence and makes new friends.
I'm not sure specifically which 'long hair bun drop story' you mean. There could be many stories related to a long hair bun dropping. It could be a simple incident where a girl with a long hair bun was running and it dropped, causing her some momentary embarrassment. Or perhaps it's a more symbolic story in a particular culture or folklore where the dropping of a long hair bun has a special meaning.
Once upon a time, there was a girl with long hair. She loved to make a bun every day. One day, she went to a ball with her beautiful long hair bun and met a prince there. The prince was attracted by her unique bun style and they started to dance. It was like a fairytale come true.
Once upon a time, there was a girl with very long hair. One day, she decided to cut it all off. She walked into the salon, sat in the chair, and told the stylist to cut it short. The stylist was shocked at first but then got to work. When it was all done, the girl looked in the mirror and saw a new version of herself. She felt liberated and ready for a new start.