Ayumu Sugino is a first-year student at Ryuumonbuchi High School and a supporting character of the "Saki" anime. She serves as a maid for the Ryuumonbuchi family and personally attends to Touka Ryuumonbuchi. She does not appear in the "Saki" manga.

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)

The Achiga Girls' Academy in Nara once defeated regional mahjong powerhouse Bansei High School. It advanced into the national team semifinals but lost to the eventual champion, and the mahjong club was later disbanded. Six years later, elementary school student Shizuno Takakamo befriends transfer student Nodoka Haramura. The two eventually enter Achiga Girls', but Nodoka transfers out of the school in the second year. When Shizuno sees Nodoka on television the following year as the national middle school individual mahjong champion, she decides to revive Achiga's mahjong club.