Jonouchi's father is a character in the Yu-Gi-Oh! manga. He is the father of Katsuya Jonouchi and Shizuka Kawai.
He suffers from alcohol and gambling addictions. After divorcing his wife, he lived with Katsuya, while she lived with their daughter, Shizuka.
Yugi, Hiroto Honda and Anzu Mazaki went to visit Katsuya at his apartment. Thinking them to be Katsuya coming home, Mr. Jonouchi fired a bottle at them, demanding to know where Katsuya had been, causing them to flee.