"Gambler" is the first chapter of Volume One of Usogui.
Madarame Baku is playing Pachinko at the same place as Kaji Takaomi. Baku doesn't notice the bonus he earned from playing, but Kaji informs him. Baku ends up getting 100,000 yen from Pachinko. As they walk down the streets, loan sharks come after Kaji. Baku pretends to be a loan shark who got sued by 'Kaji's lawyer' to make the loan sharks go away. Kaji thanks him but Baku let's him know that what he did will only keep them away for a little while.
After seeing how Kaji needs to pay back the loan, Baku promises to pay it back as a way of thanking him. The two then go to an illegal casino. Baku only drinks while observing a roulette game. After sizing up a particularly crafty dealer, he begins playing roulette. He acts as a drunk player who only bets by luck and superstition, and fools the dealer, who was actually controlling where the ball goes. In the end, Baku is able to earn a mass amount of money, ultimately, he tricks and "eats" the corrupt dealer.