SaKo, formally known as Hisako Mizoguchi, is the bassist and main composer for the idol group BanShee. She possesses multicolored hair and striking orange eyes, standing at 1.54 meters tall. Within BanShee, her key relationships are with leader RiN and sub-leader NaO, both longtime friends, alongside fellow members Tenko, Kogata, SAWA, JOKER, KONY, Sumire, Akamaru, and MINA. Information regarding her background, character development, or appearances beyond the main series remains focused on her current role in the band.