|Japanese name:||須田山 悦子|
|School:||Shindouji Girls' High School|
|Debut:||Saki, round 159|
Etsuko Sudayama is the coach of the mahjong club of Shindouji Girls' High School in Fukuoka Prefecture.
Etsuko has grayish hair and dark eyes, and is relatively tall. She wears glasses and a dark headband.
National Championship Arc
After Kirame Hanada questions her postion on the team, Etsuko tells her that she achieved great things during the regional tournament and the first round. Yoshiko Yasukouchi then draws her attention elsewhere.