Kouko Kaga
She had a perfect future planned with Mitsuo Yanagisawa as her supposed future husband, and nothing will get in her way! She happens to be Mitsuo’s childhood friend that they have been classmates in every class from elementary up to high-school, she is so into him that she would often find a way to isolate him from everyone else and even display acts hostility against any girl who would come near him.
She has a side that is not violent as Mitsuo has described, and that is her loyalty and devotion to the people who show kindness to her.
She comes from a rich family who are into healthcare business and own various private hospitals around the country.