It's not grammar then. You had me worried for a moment.
Funny you mention this one, because it was the only point I had a bit of trouble with.
It's Japanese politeness juice, "Aki-san koso" which is like, returning a compliment directed at you, and basically means "no, u".
Aki compliments Kanade about being early and Kanade answers with some modesty. I didn't really know how to render that, it's not something people do in the western world. So I just threw something out.
After thinking, I think I'll change it to "I don't want to make you wait, Aki-san". It's polite enough. Hoping there's enough room.