Miyanaga Saki is a first year high school girl whose family would get angry if she won the family mahjong games. But losing would also have its consequences. Because of this she develops a new way of playing that allows her to stay on the thin line between winning and losing, the plus/minus zero score, an almost impossible score. In a game that relies mainly on luck, the plus/minus zero score is harder than winning, but Saki can achieve this every time.<br><br>Having always hated the game, her friend from middle school, Suga Kyotoro, forces her to play in the schools mahjong club. Her developed skill and superhuman luck has made her a worthy mahjong opponent, even to the middle school's national mahjong champion.<br><br>(Source: Anime News Network, edited)