You never see/read any cyberpunk futures where people have cutlasses. Which is weird because in practice they’re the same thing as katana: a one-sided shortish sword mainly intended for slashing with.
Or, it’s just been suggested to me, an Indian tulwar. Which, like a cutlass, has better hand protection than a katana. A near-future full of tulwar. Why not?
(Or, better still, some form of gun, given it’s the future and everything)
I think my writing advice is, if you’re about to give a character a katana, stop. Swap it for a pirate’s cutlass a moment.
If it no longer feels cool, indeed, if it feels a bit corny, silly even, think about dropping the katana.