A first-year high school student. Sakiko is refined girl who comes from a rich family, and used to attend Tsukinomori Girls' Academy. She often plays the piano in the school's music room. She will become Ave Mujica's keyboard player in the future, and she used to be Crychic's keyboard player. Her family was once wealthy, but after her parents divorced and she decided to marry her father, her father began to fall into depression and drink all day long, which put her family into a financial crisis