Ukai Rei saves three troubled teens from a Suicide Website, and together they choose to work as modern-day 'Robin Hoods' of society. However, Rei's friends are caught by an underworld gang whose heist the group had foiled. In order to rescue them, Rei is forced to enter a gambling competition hosted by a rich, rotten old man who is looking for a talented gambler to be his rep player in an upcoming gambling tournament for millionaires from all over the world. The reward money? ONE TRILLION YEN.

Note - This story is directly continued in its sequel.

Japan, 1995. After graduating from high school, Itō Kaiji moves to Tokyo to get a job, but he fails to find steady employment because the country is mired in its first recession since World War II. Depressed, he festers in his apartment, biding the time with cheap pranks, gambles, liquor and cigarettes. Kaiji is always thinking about money and his perpetual poverty frequently brings him to tears.

Kaiji's unrelenting misery continues for two years until he is paid an unexpected visit from a man named Endō, who wants to collect an outstanding debt owed to him in Kaiji's name. Endō gives Kaiji two options - either spend ten years to repay this outstanding debt, or board the gambling ship Espoir ("hope" in French) for one night to clear the debt. Using a con, Endō pressures Kaiji into accepting the deal, believing he will never come back from the voyage.
--Wikipedia

The manga is divided into three parts:
Part 1: Volume 1-13 (Complete)
Part 2: Volume 14-26 (Complete)
Part 3: Volume 27-39 (Complete)
Part 4: Volume 40-? (Ongoing)

Set in 2002, 3 years after the death of Akagi Shigeru, this sequel to Ten - Tenna Toori no Kaidanji chronicles Hiroyuki's quest to follow the late Akagi's advice and live life freely even if it means complete failure.

After awakening from an eight-year-long coma, Kurosawa must face the trials of homelessness.

Tenma is a Middle Schooler who loves playing Mahjong. He doesn't know exactly why, but the freedom it brings him fills his chest with pride. One day, his friends run into some trouble with University Students from Kantou, and it's up to Tenma to save the day!