>>2816031Chapter 10 of Fudajo is complete! This completes the final battle of volume 1 but doesn't quite finish it: we've still got a chapter left to go, dealing with the fallout and such. Given the chapter title (which you can see in the table of contents from chapter 1) I've got high hopes for it.
https://mangadex.org/chapter/c13dcb39-92de-425b-85a7-ac80f0e52327>>2816118As it turns out, you were absolutely correct. And it's not an accident either, she goes out of her way to conceal it, which has interesting implications. My bet is that she was never Sana's real knight in the first place, but took matters into her own hands and decided to fight Machida while he's off-guard, explaining why this match is happening in the middle of the night with no referee.