Saki

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.

Playing under special scoring rules, Saki plays the next game while trying to keep her plus/minus zero score and winning at the same time, but cannot do both with the special rules. However, when the special rules are removed, Saki ended up winning the game, therefore disallowing her from keeping the zero score. Nodoka is dejected after losing since before Saki told her that she hated mahjong and despite that won, but Saki tells her that playing with her was fun. Saki thinks about what Nodoka said, and even tells her father that she wants to one day play again with her mother and sister like they used to before they left to be professional mahjong players. The next day, Saki joins the club, saying that she wants to play more and win against Nodoka.

It has been a week since Saki joined the mahjong club, though Nodoka is still distant to her. Nodoka plays a game by herself with all the tiles exposed and takes notes, but she is still unable to attain a plus/minus zero score like Saki who can do this flawlessly. Hisa and Mako go and sign up their club for the national qualifiers for high school students. Saki wins a game against Nodoka, Kyōtarō, and Yūki, who is depressed that she cannot possibly win when playing against both Saki and Nodoka. In the next game, Saki lets Yūki win, which makes Nodoka angry since while Saki did it so that everyone can have fun, Nodoka can only have fun when Saki is playing at her best. Saki makes a promise with Nodoka to shoot for the nationals, and the two finally become friends.

Hisa announces to the club that they are now signed up for the national qualifying tournament, and she hands out the rules. Yūki sees that one school, Ryūmonbuchi, are extremely skilled and even won the tournament the previous year despite being all first-year students. Hisa asks Saki and Nodoka to help out at Mako's family's cafe, telling them that learning about the real world is also important to improve their mahjong skills. When they arrive at the cafe, they see that it is actually a maid cafe, and they have to wear embarrassing maid uniforms. Patrons can also play mahjong there, and Saki and Nodoka easily win against two customers. After one leaves, a woman who Saki is intimidated by joins them. The woman completely mops the floor with them, and at the end it is revealed that she is Fujita, a professional mahjong player. Saki and Nodoka later find out that Hisa set the whole thing up so that they could also feel what real defeat is like. Hisa explains that the club is going on a training camp to improve their skills.

The mahjong club goes to a mountain retreat training camp to improve their skills. The first day is spent mainly having fun, and playing some normal games of mahjong. The next day, Hisa gives the first years (excluding Kyōtarō) special tasks. Saki plays mahjong online, but is dejected how easily she loses to others. Nodoka has to gain experience playing others in real life when she is more skilled playing online like she is used to when playing at home. Yūki does math drills in order to improve her ability to keep track of the score when playing mahjong. Afterwards, Yūki becomes depressed how she loses so much against Nodoka, Saki and Hisa, and the club president recounts how when she was a first-year, she was the only member of the club, but she kept with it and now she is grateful there are many new members. Yūki continues to play, and manages a win. The next day, Yūki, Nodoka and Saki go to see the nearby waterfall.

After arriving at the tournament area, Saki gets separated from her friends, and during this time Nodoka gets hounded by reporters due to her having won last year's national junior high school tournament. After Saki makes it back to the others, Hisa explains the order of the players, starting with Yūki, followed by Mako, herself, Nodoka, and finally Saki. While initially underestimated by her opponents, Yūki wins many hands, nearly shutting out the others. Afterwards, Mako and Hisa also make quick work of their opponents, ending with a commanding lead. When it is Nodoka's turn, more people show up to watch her match.