Kawai acts as a responsible girl, usually taking the role of a leader whether it be in class or on a small trip with friends. She also acts kind and polite when helping her classmates. However, at times when she is pushed, she can act rude and say mean comments about people. She is the only one who is able to tell Naoka Ueno off whenever she is going too far.

She may seem nice and polite to people but is actually quite conceited, evident in the fact that she acknowledged the fact that she was cute even from before and feels as if the class loves her. When Ishida was comatose she asked the class to make 1000 paper cranes to give to Ishida when he woke up. She found out right after that some people, in fact, know that she can be rude, and thinks the paper cranes is an absurd idea and that she can sometimes be creepy. It is sometimes hinted that she has a crush on Satoshi Mashiba, as she constantly agrees with the things he does.