Yuu Matsumi is a third-year high school student at Achiga Girls' Academy in Nara Prefecture and a protagonist in the spin-off manga "Saki Achiga-hen episode of side-A". She is Kuro Matsumi's older sister. When she was younger, she wanted to join others in Achiga's mahjong club but felt it would be awkward because she was older. Yuu is very sensitive to the cold and covers herself head to toe when she goes anywhere, even in the summer.
