Yeah I still don't get why the romance tag is there, even in the Web novel and this is pretty late in the story.
The light novel page in novelupdates straight up doesn't even have the romance tag, althought the web novel (also in novelupdates) page does for some reason. Guess just a mistag that...
He did say he forged it. How it was so sharp and the way she was carrying it before she cut the ball though, better to engage in suspension of disbelief.