I've spent way too many nights diving into the rabbit hole of 'Persona 5' fanfiction, especially when it comes to Joker and Makoto. If you're looking for quality content, Archive of Our Own (AO3) is my go-to—it's got a ton of well-tagged fics, and you can filter by pairing, rating, or even tropes. I stumbled on this one slow-burn fic there called 'Phantom Love,' where Makoto slowly uncovers Joker's secrets post-game, and it absolutely wrecked me in the best way. Tumblr also has some hidden gems if you dig through the right tags, though it’s less organized.
For something more structured, Wattpad has a mix of amateur and polished works, but you gotta sift through a lot. FanFiction.net is older but still has classics—just harder to navigate. And if you’re into Japanese doujinshi, Pixiv or DLsite might have some untranslated gems, though you’ll need to hunt. Honestly, I love how each platform has its own vibe—AO3 feels like a library, Tumblr’s like a chaotic treasure hunt, and Wattpad’s this weird mix of rough drafts and masterpieces.