The main hurdle is making a relationship feel earned when the source material barely lets them interact. 'Cowboy Bebop' gives us that one fantastic episode, 'Ganymede Elegy', and then they're off doing their own thing. So you have to build everything from almost nothing, which is actually kind of freeing, but also a trap. It's easy to fall into writing Shiro as just a moody kid and Curtis as the cool, stoic older guy, but that flattens them. Curtis has this whole life on Ganymede, a past with Jet, a code. Shiro's not just angsty; he's sharp, perceptive, and carries this immense survivor's guilt. Finding the emotional bridge between those two worlds is the real work.
Then there's the setting. They don't live on the Bebop. Their lives intersect at that bar, on that colony, in this grimy, rain-slicked underworld. So the plot can't just be 'Spike is jealous' or 'the crew gets involved.' It has to live in that noir-tinged space of bounty hunters, syndicate remnants, and barroom politics. A lot of writers try to force them into a typical romance structure, but for me, the most believable plots are about trust being built through action. Maybe Curtis needs backup on a job that's too close to home, or Shiro stumbles into trouble that reveals a connection to the Red Dragon Syndicate Curtis is tangentially aware of. The attraction simmers in the margins of that.
You also have to navigate the age gap with care, not just hand-wave it. In the show, Shiro's what, nineteen? Curtis is clearly older, more established. The dynamic isn't about power imbalance in a creepy way, but about experience and stability versus reckless youth. A good fic acknowledges that tension—Curtis's weariness with the life, Shiro's burning desire to prove himself—and lets the connection grow from mutual respect, not just physical attraction. The best ones I've read make their conversations feel heavy with things unsaid, glances across a crowded bar meaning more than any dramatic confession.