The fourth entry in Sega's MJ series of arcade games. Most notably, this installment adds a Sanma (3 Player) league, a training mode, and an improved 16:9 Live terminal. It received numerous minor updates, with features such as a customizable narrator and a visible tile wall when spectating being added, before eventually receiving a significant upgrade in 2010 called Sega Network Taisen Mahjong MJ4 Evolution.

The fourth entry in Sega's MJ series of arcade games. Most notably, this installment adds a Sanma (3 Player) league, a training mode, and an improved 16:9 Live terminal. It received numerous minor updates, with features such as a customizable narrator and a visible tile wall when spectating being added, before eventually receiving a significant upgrade in 2010 called Sega Network Taisen Mahjong MJ4 Evolution.