Satoha Tsujigaito is a third-year student at Rinkai Girls' High School in East Tokyo and a supporting character in the manga Saki. As the only Japanese-born member of her school's mahjong team, she's locked into the vanguard position under tournament rules—basically the opening player who sets the tone for everything that follows. She's a solid player too: she placed third in the previous year's national high school individual tournament, which gives you a sense of her skill level going in.
Content compiled by AnimeList.moe from publicly available sources.