|Japanese name:||八木原 景子|
|School:||Koshigaya Girls' High School|
|Grade:||Second-year high school|
|Debut:||Saki Achiga-hen, Chapter 6|
Keiko has medium length dark hair and purple eyes. She wears the standard Koshigaya Girls' uniform and a strange headband.
National Tournament Arc
She plays the captain position, and was able to bring her team through the first round for the first time in five years. In her second round match she was tasked with a 50000 point comeback, but was not able to get anywhere. Her final damaten hand actually sealed her defeat because it didn't give her enough points. After her defeat she is seen staring out a window in the tournament hallways and is given water by Sophia Arai.
Final Eight Arc
Keiko and her team were also seen after the vanguards' match at the side B semi-finals.