“My last fight was against Konayuki Itezora, who was a little girl but had this monstrous strength. Still, I won without a scratch!”
Shichika lied to his sister.
The heat of battle got the better of him.
But nothing got past her.
“Show me a liar, and I will show you a thief,” she chewed him out. “One look at you and I can tell you hurt your left arm not that long ago – Konayuki Itezora’s doing, I suppose? Still… it seems to have completely healed.”
“Just a flesh wound,” whined Shichika, flustered at being called out on his lie.

Katanagatari Omnibus 3, Page 14