Honestly, the 'enemies/rivals to reluctant allies to something more' pipeline is basically the backbone for most of the Gogo/Hiro stuff I've stumbled across. It writes itself, right? You've got this kinetic, impulsive, streetwise brawler and this methodical, brilliant, initially reserved tech genius. The friction from their different approaches to problems—Gogo's instinctive versus Hiro's calculated—creates a perfect storm for bickering that slowly morphs into a deeper, grudging respect. Then someone gets injured protecting the other, and boom, feelings realization. I've also noticed a weirdly specific sub-trope where Gogo, post-Big Hero 6, struggles with the loss of her 'death-defying thrill' high, and Hiro becomes her new, safer adrenaline rush through brainstorming crazy tech stunts together. It flips their dynamic on its head in a way that feels authentic to their characters.
Another huge one is the 'found family' trope, but with a focus on Hiro integrating into the Wasabi/Fred/Honey Lemon friend group through Gogo. She's his in, the one who initially tolerates him the least but ends up being his fiercest defender when the others might baby him. A lot of fics use her as a bridge between his new superhero life and a more grounded social circle, which is a neat twist on the usual team-as-family setup. And of course, age-gap is a constant quiet undercurrent, not necessarily in a creepy way, but more about the maturity gap. Fics often explore Gogo grappling with her attraction to someone younger but mentally on her level, while Hiro has to prove he's not just a kid with a robot. It's less about the number and more about them meeting in the middle, emotionally.