Tonegawa is who was put in charge of most of Hyōdō's events, acting as said man's right hand. He is a powerful business magnate and the third highest ranking executive in the financial firm Teiai Corporation. He was the one who sponsored Restricted Rock, Paper, Scissors, Electric Current Steel Frame Crossing, E-Card, and presumably more. A stout man of middle-age, Tonegawa is a staunch realist, a master of human psychology and the art of observation.

A manager of Teiai

Hyodo Kazuya is the youngest son of Hyodo Kazutaka and Sophie. He enjoys gambles as much as his father. He works as a novelist and a high-ranking employee in his father's company, despite being looked down on by almost everyone in Teiai. In addition, he runs a company called "Kazuya Corporation", which deals in covering up murders under the guise of suicides or construction accidents.

A young master of Teiai

He is known for his immense talent in gambling. Using his intelligence and wit, Zero conquers every gamble and becomes recognized as an undefeated genius. Despite being able to gamble with high stakes without batting an eye, he is very kind, gambling for the sake of others and to retain power in order to better the world. He is 17 years old. Cheerful personality, likes to share knowledge with others.

A genius high school student

He is the captain of the Dojima Family of the Tojo Clan and the patriarch of its subsidiary, the Kazama Family.
Despite his infamy as a merciless killer, Kazama's regret over his killings eventually drove him to open the Sunflower Orphanage, where he would finance the upbringing and education of all the children of his victims. Kazama became like a foster father to them. Kazuma Kiryu, Akira Nishikiyama, and Yumi Sawamura were amongst those children with whom he had close bonds. 

The patriarch of Kazama Family.

Talking is not very polite, condescending. But in fact, he cares about his friends very much and is a loyal person. Bad friends with Ten Takashi. He likes his son Nishikata Kyosuke very much. But he won't tell anyone his son's name unless you already know.

The leader of the underworld in Kansai.

Soft-spoken, a little flirtatious, and beautiful appearance is popular with women. Not shy at all and speaks directly. Possesses very powerful mahjong skills, and sometimes is fierce. Kyosuke especially likes Igawa Hiroyuki and Kano Riyuuji. His father is Harada Katsumi, but he won't tell anyone unless you already know.

A beautiful mahjong man

Good at calculating probability. Yukio and Yasuoka once used each other for profit, and he pretended to be Akagi, a mahjong genius, but he has no guts and is not a real gambler.
Yukio cares about rationality very much. When others propose gambling conditions, if he will suffer huge losses, he will not accept them.

Fake Akagi

Mamiya is outgoing and very confident in herself. Easy to oversleep. Often jokes or provokes others. Good natured, willing to help others, especially playing mahjong.

A genius mahjong girl.

A blind old man who doesn't talk much. He has a dull personality and is not interested in ordinary people. Live alone, not close to people. He likes dangerous, crazy gambling.

A blind mahjong master

13-year old Gai Kudo is a youth uniquely obsessed with self-reliance and independence. Living on his own and struggling to survive, he finds some sort of peace and happiness standing apart from everyone else, despite his hardships. But after being framed for the murder of the rich president of the Hirata Group, Gai is sent to the "Human Institute", a prison for juvenile offenders that seeks to rehabilitate them through torturous methods. 

A lonely and mysterious guy

Ten is a friend of Igawa Hiroyuki and Akagi Shigeru.
He and Harada Katsumi are bad friends.
He is good at joking, but he is actually a kind person.  Thoughtful, sometimes vicious. a free-spirited prodigal.

Tenhoudouri no Kaidanji.

He has worked at Teiai Group for many years and is the favored ace of Kurosaki Yoshihiro. He created the pachinko machine called the Bog. It was made in a way that it impossible for anyone to get the max payout unless he desires it to. He is Kaiji's opponent. He is shown to be very confident person. He is shown to have a superiority complex about his own abilities, and looks down on other people like Kaiji or his former classmates. However when unexpected events happens, he loses confidence.

The young manager of a casino owned by Teiai 

Washizu Iwao is an older man who has made hundreds of billions of yen and become one of the most powerful people in the underground world. He was 75 years old when he met Akagi. He genuinely thinks he is a king and speaks very mean and disrespectful.

Underground Emperor

A genius gambler who has his own unique outlook on life and loves to be alone.

Fierce God. (Middle aged Akagi Shigeru)

Nango is a down-to-earth, ordinary guy who speaks politely. A little awkward and shy. He also gambled, but he almost lost everything because of it. Nango witnessed Akagi's gambling with Ichikawa and others. He thought Akagi was a real gambler, and he had no talent for gambling.

The man saved by Akagi, the beginning of the story

He acts as Ichijō's right-hand man and is the only other person entrusted with the responsibility of adjusting the nail settings on the Bog. Anything that Ichijō needs doing, he is the first man he orders to get things done around the casino. He has an easygoing personality and is gentle with Ichijo.

Ichijo's friend and right-hand man

admire and love Akagi Shigeru.  He and Ten are friends who can fight. He is very passionate about mahjong.  Serious personality, will consider a lot.