Like what is this
Tch
Like how do you pronounce that?
Never once have I seen any characters in canon use this, except like once.
And then everyone in fanfics is like.
"Tch brat"
"Tch"
"Tch"
"Tch"
Like every sentence. Wtf?

And oui? That's French for yes.

So basically your making your characters say yes constantly.

"Oi brat" "yes brat"

"Romano-chan is blushing XD"
"Oi, I don't know what your talking about!" "Yes, I don't know what your talking about!"

Like wtf?
ARE THESE CHARACTERS LIKE SECRET FRENCHMEN???