There are fanfictions where Shinobu and Giyuu are paired in a post - demon - slaying world. For example, they might start a new life together, perhaps helping to rebuild the demon - slayer corps in a different way. Shinobu's medical knowledge and Giyuu's combat skills could be combined in interesting ways in these stories.
You can find 'demon slayer shinobu x giyuu fanfiction' on popular fanfiction websites such as Archive of Our Own (AO3). There are a large number of fan - created stories there, and you can search for specific pairings like Shinobu and Giyuu. Just type in their names in the search bar and you'll get a list of relevant fanfictions.
One common theme is the exploration of their relationship. Given their different personalities in the original work, fanfictions often focus on how they bridge the gap between them, like how Giyuu's stoicism and Shinobu's more cheerful yet calculating nature interact.
How about 'Giyuu x Shinobu: The Jealousy Factor'? This title clearly shows the relationship between the two characters and the key aspect of jealousy. It gives a hint to the readers about what the fanfic might be about, which is the jealousy that could exist in their relationship.
One great 'shinobu and giyuu fanfic' is 'The Unspoken Bond' which delves deep into their complex relationship. It shows how they gradually come to understand and support each other in the face of various challenges in the Demon Slayer world.