Karen is calm and stoic, as well as smart. Karen has a strong sense of responsibility, and is the type of person who doesn't do things half-heartedly. She has a past where she fought against many villains as a Pretty Cure in her third year of middle school. While usually calm in temperament, when pushed enough she can sometimes get to a point where she ends up saying hurtful or offensive things to other people. She was Cure Aqua, the Precure of Intelligence.