Shiromi Kosegawa, 1st year. Height: 166cm. She always seems listless, and her catchphrase is "What a drag." Her eyes are distinctive, drawn with a single point of light. Her nickname is Shiro. When she sinks into deep thought, she is usually building a high-scoring hand. She analyzes her own play not as "hesitating to make the hand higher," but rather that "whenever I get lost, the hand just happens to end up high-scoring."

Aislinn Wishart, 3rd year (appears when the main members reach their 3rd year). Height: 145cm. An international student from New Zealand. Her name means "dream" in Gaelic. Her Japanese is still broken, so she communicates by drawing pictures on a board she carries around. She has the ability to "draw" her ideal tile sequences onto the table, and is said to reach Tenpai (ready hand) while closed abnormally often by the 13th turn. She came to study abroad in the autumn of her 2nd year and was brought to the Mahjong club by Shiromi (at the same time Toyone arrived).

Kurumi Kakura, 1st year. Height: 130cm. She is strict about match etiquette and, though she doesn't say it aloud, she has a sharp tongue and a strong will. Her style involves never declaring Riichi, always staying in Damaten (hidden ready hand), and she maintains an extremely solid defense.

Sae Usuzawa, 1st year. Height: 154cm. She wears a characteristic monocle during matches. She is a skilled cook. She possesses the ability to "seal" the abilities of opponents she gazes at. However, this has the drawback of causing intense physical exhaustion when used.

Toyone Anetai, 3rd year (appears when the main members reach their 3rd year). Height: 197cm. She wears a hat and, despite it being the summer Inter-High, she wears a winter school blazer. Contrary to her cool appearance, she has a fangirl personality and gets excited when talking about strong players. She also has a side that is easily moved to tears. Known as "Sogai no Toyone," she possesses abilities related to the Rokuyo (six-day cycle) calendar, such as "Senbu" (losing first) where she chases the Riichi of an opponent and wins on the first turn, and "Tomobiki" (pulling friends) where she wins with a naked single wait after four calls.

Toshi Kumakura, Coach (appears when the main members reach their 3rd year). Height: 150cm. 53 years old. She was appointed as a high school teacher in the winter of the members' 3rd year. She used to wear a monocle but currently does not, as she lent it to Sae for the purpose of "adjusting her abilities." She suddenly appeared in the Mahjong club and excels at seeing through the traits of players. She was originally a coach for a corporate team in Fukuoka, but the team was disbanded shortly after, leading her to Miyamori. She is the one who brought Toyone to Miyamori Girls' High.