->''You... are a liar.''
-->--Bak's quote after winning a game

''Usogui'' is a psychology- and gambling- based manga by Toshio Sako.

There are gamblers out there who even bet their lives as ante. But to secure the integrity of these life-threatening gambles, a violent and powerful organization by the name of “Kagerou” referees these games as a neutral party. Follow Bak Madarame a.k.a. Usogui (The Lie Eater) as he gambles against maniacal opponents at games – such as Escape the Abandoned Building, Old Maid, and Hangman – to ultimately “out-gamble” and control the neutral organization of Kagerou itself.

!!''Usogui'' provides examples of:

* AbsurdlyHighStakesGame - The entire premise of the story.
* BatmanGambit - Bak uses his opponents' personalities against them. Q-Taro found this out the hard way when Bak recruited [[HeelFaceTurn Marco]] during his battle with him. He used Q-Taro's belief that Marco was dead to lure him out and attack him with Marco.
* Catchphrase: "You are a liar", told by Usogui, mostly every time he is about to defeat his opponent.
* GambitRoulette - Some of Bak's plans seem to be this. [[AvertedTrope But he actually does try to learn everything about a target,]] down to their personalities, forces, and [[CrazyPrepared supplies they would have hidden in their building.]] Yes, he even plays roulette this way.
* HeelFaceTurn - Marco joined Bak's side after asking Bak who he was. Bak's response: "That's something you must decide for yourself."
* SeriousBusiness - Bak treats slots as such. But his entire life has been about life-or-death gambling, [[JustifiedTrope so...]]
* SuperPoweredEvilSide - Do ''not'' stick a syringe in Marco.
* TrademarkFavoriteFood - For Bak: Japanese apricots. Eating one usually means he's about to do something badass.
* XanatosGambit - All of Bak's strategies are these. If an opponent calls his bluff, he reveals that it wasn't a bluff and wins anyway.