Kaiji Itou is a loser. He's been out of school for two years, has no job and lives in a tiny Tokyo apartment while spending away his meager savings on food, rent, beer and cheap entertainment. To pass the time, Kaiji defaces luxury cars and steals their hood ornaments (his excuse: "Those rich assholes had it coming!")
But things are about to get a lot worse for our hero. After cosigning a huge loan for a friend who ends up in default, Kaiji receives a friendly visit from a Yakuza loan shark who presents him with a unique opportunity to get out of financial trouble.
A luxury liner, the Espoir, is getting ready to leave port and go on an overnight cruise. On this one night, the Espoir will carry hundreds of other men in dire financial straits and give them a shot at repaying all of their debts by competing against each other at an undisclosed form of gambling. Those who win will be freed from their crushing debts, but those who lose face even greater debt that they'll have to pay off by working as forced laborers for the shady finance firm that's sponsoring the cruise.
Kaiji, knowing that he has no hope of working off the millions of yen he now owes to the Yakuza, agrees to board the ship and join this mysterious game. What Kaiji doesn't realize is that he's about to enter a world of bizarre and dangerous gambles, of mind games, of temporary alliances and backstabbing, of corruption and even of death.
Kaiji (also known as Ultimate Survivor Kaiji, Gambling Apocalypse Kaiji and a few other titles) is a manga series produced by Nobuyuki Fukumoto, one of Japan's most famous and prolific comic writers.
If you're looking for catgirls, comically perverted situations and other common manga elements, don't look for them here. Most of Fukumoto's works revolve around mob-related gambling and bear no resemblance at all to "that cutesy anime crap" as a friend calls it. But anyone who's read one of Fukumoto's stories knows that they're about a lot more than just desperate gamblers, crooked cops and menacing Yakuza thugs. The nature of power, risk, trust and the will to survive are all essential elements of Kaiji's story.
In every one of his story arcs, Kaiji is placed into an absurd situation where he has to risk life and limb to win large amounts of money to pay off his debts. These insane games are operated by Teiai, a shadowy mob-connected finance firm headed by an old half-crazy billionaire. Most of the trials that Kaiji faces are zero-sum games: if one man wins and gets away with his life and his debts erased, another man loses everything.
One game involves a race across three narrow metal beams suspended between two platforms about 7 or 8 meters off of the ground - not high enough to kill, but certainly high enough to break some bones and cause serious injury. There are fifteen racers, and the first two across win. Kaiji must answer a question in his mind: Should I push my opponents off the beam and advance, or should I allow myself to be pushed off by the racers behind me?
Often, the games' designers will stack the odds against their indebted players in ways that are not immediately obvious. In these cases, Kaiji will have to use his reasoning skills under extreme pressure to figure out how to outsmart his oppressors and achieve victory.
I won't spoil anything else - most of the excitement of Fukumoto's works comes from the state of near-constant suspense that the reader shares with the protagonist. But it's evident from the very beginning of the story that Kaiji Itou is a special man. Under normal circumstances, he's weak-willed and unmotivated: a complete loser. But when his life is threatened, he seems to unlock amazing abilities that allow him to survive, all while trying to maintain his humanity in situations where doing so can cost him everything.
Kaiji has been released in four parts since 1996, but Kaiji's story is still far from over. Fukumoto seems to enjoy working on four or five projects at once, so it may be a while before the series finishes. The series has never been licensed for publication in the US, probably because of its niche appeal, but English fan-translations of the comic are floating around online.
The first two series of Kaiji have also been adapted into anime form. The Kaiji anime is very faithful to the source material and adds a lot of visual spectacle and a fantastic soundtrack to the story, so I'd say it's well worth watching. Just don't expect to see an actual ending anytime soon.