He is tall and has dark skin. He has dark blue hair with white highlights and is often seen in either a business suit or a lab coat considering that he works as a doctor. He also has a moustache and glasses. Comparing his overall appearance to his son and daughter, they do not look alike that much, where his daughter resembles his wife more. However, his eyes are somehow similar to those of Gouenji's. In the game younger Katsuya doesn't have a moustache (though in the anime he does) and wears yellow collar shirt, white vest and dark blue pants.
As shown before, he used to love soccer and was also passionate along with the whole family. He was happy to see his son play soccer and would always attend the matches his son was into, but after his wife's death, his point of view about soccer has changed completely. Added with his daughter's accident, he starts forcing Shuuya to quit soccer and convinces him to study medicine in Germany. However, having seen his son play against Fire Dragon, he let him continue playing soccer. In the end, he was happy for his son.
He first appears in episode 79 where he started to talk to his son, stating that he will quit soccer and start studying in Germany to become a doctor like him to which made Gouenji shocked and angry. Because of this both had an argument.
Katsuya stated that soccer cannot take back the lives of people that are gone, it can only inspire people but cannot take back lives. That is why he wants Gouenji to become a doctor.
Though, Gouenji made a deal with his father, stating that he will agree only if he can play on his last match, which would be against Fire Dragon. His father agreed and later on the match started and he watched his son play.
Because seeing his son play, in the end, he decided to let Gouenji continue playing soccer.
In the Inazuma Eleven 3 game, Katsuya talks to Gouenji about him quitting soccer to pursue his studies to which Gouenji does not approve, but he has no choice but to follow him.
Later, Endou finds out about the Gouenji family's past and that Gouenji may quit the soccer team so he rushes to the hospital and talks to Katsuya asking Gouenji to stay, but instead receives no reply and Katsuya leaves Endou.
When Inazuma Japan triumphs and wins the match, Endou notices that Gouenji wasn't around afterwards, he rushes to the hospital and sees that both Gouenji and Katsuya are talking. In their discussion, Katsuya lets Gouenji continue playing soccer to which makes Gouenji happy.
In the ending of Inazuma Eleven 3: Sekai e no Chousen!!, he can be seen playing soccer with his son.