A classic gamin. One day Jonouchi (in the US version - Joey) decides to harrass little Yugi, but despite this Yugi helps him when he needs it. Yugi's goodness attract Jounochi and they become best friends. Yugi's grandpa teaches Jonouchi the rules of Duel Monsters. Though he is not recognized in this game Jonouchi has the support of Yugi and becomes a really good duelist.
In the Duelist Kingdom he finds a new friend - the self-confident Kujaku Mai (in the US version - Mai Valentine), after he defeats her with the help of the Time Wizard (a card Yugi gave as a gift to him). In this tournament, thanks to the same card, he manages to win from Rex Raptor the Red-Eyes Black Dragon, which becomes his favourite card. He is the runner-up in the tournament after he loses the final to Yugi, but Yugi gives Jonouchi his money reward in order to help him pay for Shizuka's operation (in the US version - Sereniti). Jonouchi values his sister a lot because as kids they are separated. That is why he takes care of her however he can.
In the later episodes of the anime he is considered to like Mai but we never find out if this is true.
His main oponent is Seto Kaiba who considers Jonouchi a loser. Jonouchi never manages to beat Kaiba in a duel.
Translated from Bulgarian language by: Ted^Maverick (TV_Squad)