Nationals
All the schools gather for the training camp where Yumi gives Hisa some data on the other opponents in the nationals. Later on, nearly everyone takes an interest in ping pong (that ended with Tōka dominating over everybody who participated, prompting Saki and Nodoka to stay by the sidelines) while Mako and some others fail to get revenge on Kaori's beginner's luck. The next morning, some of the girls go in the onsen to discuss the powerhouses of the nationals, including Saki's sister, Teru. Hisa's suspicion of Saki as Teru's younger sibling was confirmed by Saki's reaction when she confronted her of this fact. Saki is a bit shocked to hear from Mohoko that Teru had denied having a sister, so Nodoka decides to take her to a shrine to cheer her up. Afterwards, they exchange souvenirs and decide to call each other by their given names. After they get back, the training starts in a room where the players from Kiyosumi, Ryūmonbuchi, Kazekoshi, and Tsuruga are already seated and ready to play, with Hisa also having invited Fujita to join them. Kiyosumi prepare themselves for the nationals.
Aired 28/09/2009EP 25 - Nationals
Saki
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.
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.
(Source: Anime News Network, edited)