Alright, let's talk Luffy x Usopp (LuSopp? Luppy? I never know what to call it). It’ s a rarepair, for sure, but that just means you can get really creative with the genre. Personally, I think hurt/comfort and adventure are a fantastic fit for them. The dynamic is built on it: Usopp's fear versus Luffy's unwavering courage, and the deep, genuine loyalty between them. You can really dig into the aftermath of big moments, like post-Water 7 or after a brutal battle, exploring how they mend things in their own weird way. Usopp patching Luffy up while muttering about how reckless he is, Luffy just grinning through the pain because his friend is there—that's the good stuff.
Outside of the heavy stuff, I've seen some amazing AU genre flips. Fantasy AUs where Usopp is a wizard who accidentally summons a chaotic fae king Luffy, or sci-fi settings where they're rogue spaceship crewmates. The contrast works so well there too. I once read a modern coffee shop AU that somehow nailed their dynamic perfectly—Usopp as a barista inventing wild drinks, Luffy as the customer who orders them all. It shouldn't have worked, but it did.
Honestly, I think people sleep on domestic or slice-of-life for these two. They share a dream, but they also share a home on the Sunny. Seeing them just exist, with Usopp tinkering and Luffy napping nearby, can be incredibly warm and character-driven without needing a world-ending plot.