Yes, there are quite a few. You can start by looking on fanfiction platforms like Archive of Our Own. There, you'll find a variety of stories that explore the relationship between Utahime and Gojo. Some might focus on their past interactions within the Jujutsu Kaisen universe, while others could be more creative and imagine different scenarios for them.
One common theme is the exploration of their relationship. Since they have an interesting dynamic in the original work, fanfics often expand on how they might interact more closely.
One great 'gojo and utahime fanfiction' is 'The Unlikely Bond'. It beautifully explores their relationship in a world full of magic and mystery. The story focuses on how they start from being just colleagues to developing a deep connection. Another one is 'Gojo and Utahime: A Different Path' which takes a unique approach by showing their adventures outside the typical scenarios we see in the original work.
In many 'gojo and utahime fanfic', a frequent theme is the power dynamic. Gojo is extremely powerful, and Utahime has her own abilities. Fanfics play with how this power difference affects their interactions. Also, the theme of hidden feelings is quite common. They might not show their true emotions openly, and fanfics like to dig into that and bring those feelings to the surface. Moreover, the theme of teamwork and how they can rely on each other in difficult situations is also often explored.