I suspect its because of the "metal clan thing". Maybe she is from another "element" clan and they kinda react to each other? The girl was frightened so she is from the wood clan because metal suppresses wood? Therefore she was frightened and he kinda angry? I am just speculating.
@Cybergame
I went the simple route and thought it's because she's lost important people to her due to the metal clan, though your explanation does make sense due to how Noh was giving off his bloodlust despite this being their first ever meeting
I kind of like the shivering/worried lady introduced to Noh as a wife candidate this chapter more...though they are very likely to fight at this point, from how the plot is shaping up as a cursory theory.
Don’t fuck it up! Don’t you dare! This has been building for years! You get the kids you get Noh, just fucking don’t make them call you uncle. I swear.