松実 宥

Yuu is a third-year at Achiga Girls' Academy and the older sister of Kuro. When she was younger she wanted to join with the others in the children's mahjong club but she felt it would be awkward because she was older. She is very sensitive to the cold, so she covers herself head to toe when she goes anywhere. Yuu is polite, shy, and a bit of a push-over. However, she can be determined at times, refusing to buckle even when faced with unfavorable situations, and being determined to win back any points her sister lost. She also has a strong relationship with her sister.

Yuu's ability is that she can draw alot of manzu and chun (red) tiles, so her hand is manly composed of these tiles. She also draws these tiles because she feels warmer drawing in warm tiles. As a result, her tile possession distribution is generally skewed toward the character tiles. When that playing style fails, Yuu draws in all red tiles and becomes difficult to defend against.