Context : 2 character are talking ,they're seems to be the student at a magic school
C2: あ、あはは…なんか、ここって愉快な人が多いのかしら。ちょっと思ってた感じとは違うなあ
C1: もっとキッチリした性格の人とか、捻くれた魔術士ばっかりだと思ってた?
Later on C2 thanks C1 ,because she said will guide C2 around the school and introducing her to people C1 knows about
C1: お礼は食堂のスィーツでいい
C2: あ、そういうところはキッチリしてるんだ
What does this expression mean about one person's personality ?