Uraraka and Deku do get together in the manga. It happens as their friendship deepens and they face various challenges together, leading to a romantic connection.
Typically, these fanfics often focus on their relationship, whether it's friendship or a budding romance. They usually incorporate elements from the original 'My Hero Academia' universe, like their hero training and the challenges they face at school.
One common theme is their mutual growth. They both are on the journey to become great heroes, and fanfics often explore how they inspire and help each other to grow. For example, in many fanfics, Uraraka's positive attitude helps Deku when he's feeling down about his progress.