|Japanese name:||利根川 幸雄|
|Talents:||Acting and reading others|
Yukio Tonegawa (利根川 幸雄, Tonegawa Yukio) is a man who was put in charge of most of Kazutaka Hyodo's events, acting as said man's right hand. He was the one who sponsored E-Card, Human Derby, Rock-Paper-Scissors, and presumably more. He served as the main antagonist of the first series of the manga, and served as Kaiji's opponent in E-Card. However, he was defeated by Kaiji in E-Card, and was forced to apologize to Kaiji for all the misfortune he had caused him and his friends earlier. Then, Hyodo replied that no matter how much a person begged for forgiveness, they would never truly mean it, and then brought out a smoldering frying pan, where he forced Tonegawa to kneel on it to Kaiji out of his sadistic pleasure. Tonegawa, now heavily burned and unconscious, was dragged away by his men in defeat. Tonegawa's fate is left unknown after that, however it is certain that he was demoted from second-in-command of the Teiai Corporation.