The mother of the four famous Sugimoto sisters. She is at a more mature age than the other parents in the series, as she has three adult daughters and one who is in her last year at high school. Perhaps due to her age, she is wiser and less surprised by things. She is a little shocked when Yasuko announces that Fumi is her girlfriend, though most of this might have come from the news that her youngest is actually dating rather than the fact that they're both girls, as she quickly gets over her surprise. She is very open-minded and accepting as seen during the talk she, Shinako, Kazusa and Kuri have about the nature of Yasuko and Fumi's relationship. She even suggests rather casually that Yasuko might have already had sex with Fumi as far as they know (much to the exasperation and embarrassment of the elder daughters). It thus seems that Yasuko's lifestyle does not bother her. It appears that she was quite popular just as her daughters were back in her "glory days" and her daughters often make fun of her for regaling visitors with stories from her past, citing that she will take any opportunity to talk about her youth.