Katsuhiko was Adobted by Mrs. Minagawa after The Death of His parents in Car Accident for 7 Years
He is Very Bad Person Who Doesn't Respect For Himself. He Also Pick Naomichi like this and Hurt Kaori's Feelings.
As Katsuhiko being a Bad Guy. He has close Friends but He never like them.
Katsuhiko and Kaori are Childhood Friends jus like Shinichi and Ran. Kaori Doesn't like Katsuhiko's Dealing. Katsuhiko always Hurt Kaori's Feelings.
Yoshimi likes Katsuhiko although Being a Bad Guy.
The two met each other. Naomichi always hated Katsuhiko and Naomichi was trying to kill Katsuhiko but failed.