The protagonist you incarnate. Seeing school as a mere method to avoid stress, Kyousuke is an average high schooler, lazy with studies and hanging around with his friends, especially Eiichi. What he likes? Money but that's related to his lifestyle which isn't exactly as the appearances seem to be. The other true hobby he has a fond of is classics, especially Bach, and "Air on the G string".
Kyousuke will quickly show some deviant morals as Gonzou's "education" will have a certain impact on him: because of specific circumstances, Kyousuke will be obsessed with money and his efforts and genius business skills will permit him to be trusted well by Gonzou.
As the story goes on, Kyousuke will be hit by the reality and will soon realize what he lost during all these years, with his bound with either girl, but that's not as easy as it sounds to be.