Katsuo is one of the most important characters in the game. He is the "rival" or the "problem child" of the game. He is infatuated with Mitsuki, admiring her positive attitude. He builds up this villain-like persona throughout the story, only to have it all crumble at the end. He was raised in a high class family, so he is mature. He also loves toying with people's emotions and minds, trying to find out exactly what makes them tick. A soft, mid-ranged voice is preferred.