Yumi Kajiki is a third year student and captain of the Tsuruga Academy Mahjong team. She is a calm and very determined girl, an aspect that has shown itself in and outside of Mahjong. She is a very skilled Mahjong player, able to not only hold her own against both Saki and Koromo but she was even able to counter the former; she was able to figure out Saki's strategy within two Hands and counter her perfectly. Whilst she herself deemed that one moment as pure luck, she is shown to be a strategic player. She, like Hisa, is also able to grasp concepts at a fast pace, picking up on subtle things that others wouldn't notice immediately.