Toua is a successful gambler, and a pitcher in the game One Outs. After losing a game of One Outs for the first time , he joins the Lycaons with an odd contract, the One Outs contract, that decides Toua’s pay based on his performance. As the Lycaons’ famed star pitcher, he can pitch entire games without giving up a single hit.
Later on in the story, Tokuchi purchases the Lycaons club and implements many of his own rules in order to win the championship.
Major manga spoiler(ending):
After Lycaons win the championship, Tokuchi is relieved of his promise which he made to Kojima at the start of the series(which was to join Lycaons and help them win the championship).
Because the bet/”game” has ended, Tokuchi leaves the team without saying a word, and is never seen again.