Kaminashi's first friend and rival. Before Keijo used to be a judo's athlete, she was the Japan's hope for a golden medal in the Olympics but threw it all away in the qualifications. She has a complex about her bust size and Kaminashi usually makes fun about it. She previously resided in Room 309 before being promoted to the Elite Class. Upon graduating from Setouchi, Sayaka officially becomes a B-Rank Keijo player, affiliated with the Kansai's Hyougo Branch.