Some tropes really thrive in a context where canon isn't all that chatty, and with Kakyoin and Jotaro, you've got perfect soil for that. The 'ten years later' reunion, post-Stardust Crusaders, is a classic. It lets you flesh out Jotaro's marine biologist path and explore a Kakyoin who lived, but with scars—both emotional and maybe physical. That scenario lets you build a connection from shared history they never really had time to unpack. It's less about rehashing the adventure and more about two adults figuring out who they are to each other after the world stopped needing saving.
Then there's the bodyguard trope, but flipped. What if Jotaro, still feeling responsible, ends up protecting Kakyoin from a lingering stand threat, years down the line? It creates this forced proximity, a reason for their stoicism and sharper edges to constantly rub together, which can lead to some fantastic friction-turned-softness moments. You can see the evolution from duty to genuine care. I've read a few that nail this, where Jotaro's protectiveness becomes less about obligation and more about a quiet, personal vow.
Honestly, the angsty 'ghost Kakyoin' or 'memory' fics aren't really my speed, even though they're popular. They often get too bogged down in Jotaro's guilt and it becomes a one-man show. I prefer stories where they both get to be present, flawed, and slowly figuring it out.