Karen is a very shy and unsure person, who likes it when someone is leading her and she´s not very good at deciding or standing up for herself. But she still has a very friendly and kindly character and is not able to hurt people or animals. She always dreamed of meeting her true love one day. She is also seen been picked on by Mizuno alot.
Karen also has to know Kyoko very close, cause she realizes very fast, that Kyoko is only pretending to love Hizuki.
Karen has been a friend of Kyoko, since they went together to school. When Widoseek gets to near to Karen, she´s rescued by Kyoko. In the 2. book she falls in love with a guy called Mitsuru, who becomes her boyfriend, because she´s not allergic to him. When she tells Kyoko, the princess is a little jealous and wants to meet Mitsuru. But when she goes to his house, she only meets Widoseek. Who tells her that Karen has been taken to a special show by Mitsuru, where she´ll be sold. Kyoko help Karen escape, but when they escape, Mitsuru follows. On the chase Mitsuru nearly drowns and Karen rescues him and thanks him for what he done for her, That´s when her godness-stone accepts here and she becomes the "Flower Stranger".
She forgives Mitsuru, but doesn´t stay with him. She helps Kyoko fighting diffrent demons and finally waking up Ui. When Kyoko returns from her real father, Chronos, Karen has already found a new boyfriend: The "Bird Stranger" Toba, to who she isn´t allergic, too.
Karen is a very good and keen dancer. She also danced with her clan at court, when Kyoko had her "coming-out" about beeing a princess.