Sure. One great place to find shirou x mina fanfiction is Archive of Our Own. There are many well - written stories there that explore their relationship in different ways, like some might focus on their adventures together in a fantasy world, while others could be more about their emotional bond in a modern - day setting.
There are also some shirou x mina fanfiction on FanFiction.net. You can search for it using the relevant tags. Some stories might be about how they meet for the first time and how their relationship gradually develops over time, with interesting character interactions and plot twists.
You could also try looking on Wattpad. Some authors there create unique shirou x mina fanfiction. For example, there might be a story where they are both part of a secret society and their relationship is tested through the various challenges they face within the society.