Well, it often has a lot to do with the character development. The unpopular girl usually has some really great qualities that the popular guy discovers over time. For example, she might be really kind or have a great sense of humor. And as the popular guy starts to see these things, the readers get to see his perspective change, which is interesting. Also, for female readers, it can be a bit of a fantasy to be noticed by the popular guy who sees something special in them when others don't.
It's the idea of unexpected love. People like the concept that love can happen between two people who seem so different in terms of social status. It gives hope that there's more to a person than what society labels them as.
It often allows for character development. The popular girl can learn to look beyond surface - level popularity and discover true value in someone. The unpopular guy, on the other hand, can gain confidence. For example, in a story where the unpopular guy is into astronomy and the popular girl initially mocks him but then becomes fascinated by the stars through him. Their relationship becomes a journey of self - discovery for both of them. This kind of growth and change in the characters makes the fanfiction really engaging.
One example could be 'The Duff' which was later made into a movie. In this story, the popular guy starts to notice the so - called 'duff' (designated ugly fat friend) in a different light and they develop a relationship.
The unpopular girl can be developed by showing her hobbies. For example, if she loves painting, it can be a way for the popular guy to see her creativity and passion. Also, her relationships with her family and friends can be explored. If she has a really close - knit family or a very loyal friend, it shows her value. And her dreams for the future, like wanting to study a certain subject or travel to a specific place, can make her more complex.
One common plot twist is that the unpopular girl has a hidden talent or passion. For example, she might be an amazing artist or a brilliant writer but keeps it to herself. When the popular guy discovers this, it deepens his attraction. Another twist could be that there's some kind of misunderstanding or interference from the popular guy's friends who don't approve of the relationship. They might try to break them up, but in the end, the guy realizes his true feelings and stands up to his friends.
You can also look for these fanfictions on Wattpad. There are often communities dedicated to different types of romantic tropes. The unpopular guy in these stories might be an outcast because he's a bit nerdy or doesn't fit the typical 'cool' image. But the popular girl, who might be tired of the shallow relationships in her popular clique, is drawn to his authenticity and unique personality.
In these fanfics, the 'shared interest' trope is often seen. For example, they both love a certain type of music or literature that no one else around them cares about. This shared passion becomes a strong bond. Then there's the 'unexpected encounter' trope. They might meet in a really strange or unexpected place that makes their connection seem fated. And the 'protective instinct' trope can also be present. The popular guy feels the need to protect the unpopular girl from the mean remarks or actions of others.
However, it could also go the other way. There might be jealousy from other girls or even some guys who don't like the idea of the popular guy being with an unpopular girl. They could start to spread rumors or be mean to her, which could potentially make her social standing worse at first. But as the relationship develops and the guy stands by her, she might gain more respect in the long run.
They're popular because it's a very relatable concept. Many people have had a crush on someone and felt that sense of obsession at some point. It's also a bit of a fantasy for some, seeing someone be so dedicated to another person.
The theme of transformation is often present. The unpopular girl might transform in terms of her confidence and social standing. The popular guy may also transform in his values and how he views the world. For instance, in some novels, the popular guy starts to see the importance of authenticity and kindness which he learns from the unpopular girl. This mutual transformation is what makes the relationship in these novels so interesting and engaging.
It's the contrast. The villain is usually associated with bad things, and when they fall in love with the heroine, it's a complete change. It's like seeing two opposite poles attract.