I went on some puddle-deep dive into Chinese swords and there seem to be a bit of anachronism in Kaedegami
What's more common for use in contemporary time is actually a dao (刀) that's single-edged and curved instead of a jian (劍) that's double-edged here >>282086362
Jian was more commonly used back during the ancient times pre-1000s, but because it was double-edged (harder to maintain and too rigid) it fell out of fashion against dao, and usually is only used by nobles. Though maybe Chiyou using a jian instead of dao makes sense here because she's old, but not Huazi.
You can funnily enough trace back where the Japanese got their katana from. They're from dao (刀, katana in Japanese) and not jian (劍, similar to 剣, tsurugi in Japanese).
So if you found a shonen manga ultimate moves that goes yada yada no tsurugi then that was originally based on the jian instead of dao.
The more you know.