Finally, a question practically MADE for me!
My main character's sword is a katana. Are they overused as hell? Yeah, kinda, but they're what my main character trained with. They also have perhaps the best retention system of any medieval-era sword, which makes them uniquely suited for usage in a daily-life kind of environment. June also has a wakizashi(and yes, she knows how to wear her swords together properly), though for practicality reasons she rarely pulls that one out.
(I'm actually considering inverting the "learning da eastern fighting style" trope way later on down the line by having June actually study HEMA).
IRL, I'd probably prefer a longsword, greatsword (zweihander or montante, I'm not too picky), or sabre. If we're aiming for style points, sabre or messer would probably be my picks.
I'm actually super passionate about having good choreography even within the context of novels, and I think it shows quite well.