Sanity Slippage: Subverted. He is pretty much off his rocker by the time the events of the story take place. He's even willing to go so far as to build an underground "kingdom" then deliberately trigger nuclear war to hold onto his power, leaving the entirety of the lower classes to die in the initial bombings.
Easily Forgiven - Despite having scammed Kaiji in the past, he gets off the hook pretty quickly.
Ungrateful Bastard - He accepts Andou's offer to betray Kaiji at the end of the Espoir arc. This is pretty horrible when you think about it, since Furuhata was responsible for Kaiji's debt in the first place.
Secret Test of Character - In the manga, they offered more of Otsuki's money to Kaiji than anyone else; this was actually a test to see what a guy he really was. If he had accepted it, he wouldn't have gotten any at all. In the anime, they never mention this.
Smug Snake - For a man who for all intents and purposes works as a slave, he sure is condescending.
Too Dumb to Live - When Yoshihiro interrupts their second game, he tells him to leave in a rude way. Never mind the fact that Yoshihiro is the only one there who wears fancy clothes instead of the standard labouring uniform, and that he's accompanied by several black suits.
IchijouThe young host of an illegal casino famous for its pachinko machine the Man-Eating Bog, which promises a really big payout, but is in fact impossible to win at. Without tricks, that is. He also works under Teiai.
Villainous Breakdown: Loses his coolness near the end of part 2, and makes some pretty crazy facial expressions.
We Will Meet Again - After his defeat, Ichijou gets sent to the "hellhole". Kaiji feels bad for him and calls him a Worthy Opponent, asking if he will get back to get revenge. Ichijou's answer is "Of course". At this point it's unknown if he will keep his promise though.
Who's Laughing Now?: He's waiting long and hard to invoke this trope against his old friends, who bullied him for not having a respectable job.