Mizushima Yayoi

Principal Ranka's daughter, and Aoi's mother. A relaxed and calm woman whose mere existence exudes an air of motherliness. She's an art teacher, well-liked by her students. (Who have given her the nickname "Yayo-tan.")

Because she doesn't have a husband, she dotes excessively on her son and is very distraught if he doesn't return her affections. She was very happy to welcome Aoi back into her home after his long absence.