The second son of Kazutaka Hyoudou, a spoiled child who loves gambling as much as his father. Having only been treated falsely throughout his entire life, by people who only wanted to use him for his money or pleased him to avoid retribution, Kazuya does not understand human bonds and believes that friendship and love are simply lies that will fall away at the last moment. He also seeks to become an acclaimed author, believing that, this way, he will get true acceptance and praise, not merely humored by people who hate him for his father's sake. After Kaiji disagrees with his outlook on life, he sets up a "Salvation Game" to put their contradictory worldviews to the test and see which is true, and which is false.

Spoiler

After Kaiji defeats him in One Poker, he falls from the great height of the building as the condition of the loser, but Kaiji, Chang, and Mario manage to save him from the fall as an act of mercy. He is shown to be unconscious after they leave him to escape with the money he bet. Enraged with his son's condition and the loss of 2.4 billions Yen, Kazutaka commands the blacksuits and Endo to capture Kaiji, Chang, and Mario to get the money back.