[During] I am so sorry '''orz
[ Kohran had a lot of things going about her mind today, and admittedly, she's not the most focused so the exam had really come at a bad time!
She remembers Ukitake-han from the prom and so when they had been paired for the first part, she feels intimidated and feels bad to have to "hurt" him so as she can defend herself since he had been so kind to her that one time. But she had indeed seen what he's capable of in the past classes.
Kohran is so mentally unprepared -- which can turn out well for the purposes of the class, or really really bad exam-wise. ]