After getting roped into a former coworker's debt as his cosigner, Kaiji Ito finds himself stuck with an astronomical amount of debt. The loan shark Endo gives him one last chance - get onboard the gambling boat Espoir and win his freedom back by facing aimless young people in the same situation as him. There's just one problem - a fate worse than death awaits those who lose on the Espoir.
Gambling genius Zero saves three teenagers from their group suicide attempt and convinces them to work with him, acting as "Robin Hood" and returning swindled money back to their original owners. But when the swindlers themselves catch their ragtag team, one thing leads into another, and suddenly they're all being invited to Muryo Zaizen's big tournament - a gambling free-for-all where the stakes are high, and the mortality rate is higher! With nothing but his quick wit, can Zero get out of the competition alive?
Kurosawa is sick and tired of his boring, ordinary life growing old as the less popular site foreman in Anahira Construction. The turning point comes when his 44th birthday comes along, and no one remembers or celebrates with him. Realizing he lived a life without drive or purpose, Kurosawa tries to go past his comfort zone to turn his life around. Will his newfound shenanigans help him or hurt him when he gets caught up in fights with delinquents?