In this case, she want to say kega (injury) but mixed with kiss, hence kesu.
HOWAaa?!Are you alright?
You weren't injured, right?Kesu?I... I didn't...
K... I didn't Kesu at all!
Kiso seems to be slurring "kisu" (kiss) here with "kega" (injury), although "kesu" is also a word that can mean something like "erase", hence Admiral's confusion.
