Saki Miyanaga is a skilled mahjong player, but she hates the game since she would be punished by her family whether she won or lost when she played with them. Upon entering high school, Saki's friend, Kyōtarō Suga, takes her to their school's mahjong club so Saki can be a fourth player. There, she meets Nodoka Haramura, a very skilled mahjong player and previous junior high champion, and Yūki Kataoka, an energetic first-year who is skilled in mahjong though has trouble staying focused. Saki only plays a few hands and leaves shortly after the club president and student council president, Hisa Takei, wakes up. Hisa notices Saki managed to keep her score at zero, a difficult feat. Hisa manages to get Saki to come back the next day to play a couple more games with Nodoka, Yūki, and Mako Someya, a second-year member of the club. Saki shows her skill in mahjong by attaining the zero score in the first game.