One possible theme could be adventure. Maybe jotaro and kakyoin go on a journey together on horseback, facing various challenges along the way. Another theme might be friendship. The horse could act as a symbol of their bond, something they take care of together and through which their relationship deepens.
One possible plot could be that Kakyoin and Jotaro come across a mysterious horse in their adventures. This horse has some special abilities related to the 'Stand' powers in 'JoJo's Bizarre Adventure'. They then have to figure out how to handle this horse and how it might be related to their mission.
Well, finding 'jotaro x kakyoin horse fanfic' might be a bit niche. However, you could also check out some JoJo's Bizarre Adventure fanfic communities on Reddit or Discord. There, fans often share and discuss their favorite fanfics. Maybe someone has come across or even written a story about jotaro and kakyoin involving a horse in those communities.
There might not be a lot of fanfic specifically focused on 'kakyoin x jotaro horse'. It could be a rather niche concept. You may need to look through general fanfic collections about these characters and see if there are any that incorporate the horse element in an interesting way. For example, perhaps a story where they go horse - riding together in a particular setting within the 'JoJo's Bizarre Adventure' universe.
He could meet his past allies in a different context. For instance, he might encounter Kakyoin or Polnareff when they were just starting their journey. Maybe he could also run into Dio at a time when Dio was still plotting his rise to power, which would create a very tense situation.
Well, 'Jotaro's Redemption' is an interesting jotaro fanfic. It shows Jotaro dealing with the consequences of his past actions and trying to make amends. 'Jotaro in the Parallel World' is also quite cool. In this fanfic, Jotaro is transported to a parallel universe where things are very different from his own world. He has to adapt and find his way back. Then there's 'The Secret of Jotaro' which uncovers some hidden aspects of his character.
Once upon a time, Jotaro was on a long journey. He had been traveling all day, fighting off strange creatures with his Stand. As the night fell, he found a small, cozy cave. He made a fire using some dry branches. Then, he sat down and started to think about his friends and family. The warmth of the fire made him drowsy. Slowly, he lay down, using his hat as a pillow. With the sound of the crackling fire and the wind outside, Jotaro drifted off to sleep, ready for whatever new adventures awaited him in the morning.
Jotaro was in a forest. It was getting dark. He used his Stand to find a safe place to rest. He found a large tree with a hollow at its base. He crawled inside and made himself comfortable. He thought about all the times he had been in dangerous situations. But here, in this quiet forest hollow, he felt at peace. The sounds of the forest at night, the hooting of owls and the rustling of leaves, were like a lullaby to him. He closed his eyes and soon was fast asleep, his Stand standing guard over him even in his dreams.