Jounouchi is Yuugi’s best friend. At the beginning Jounouchi used to bully Yuugi; however, after being saved by Yuugi from an even more of a dangerous thug, Jounouchi has been pals with Yuugi ever since. Jounouchi likes to hang around with Yuugi and learns a lot of new games. He is not always confident that he will win his games, but he always tries his best.
He enters the Duelist Kingdom Tournament to get money for his sister, Shizuka, who is losing her eyesight. He wants to use the money for her surgery.