Saki Satou is Ichiro Sato's 36-year-old mother and a childhood friend of Kana Kojima, despite their age difference. She shares a hometown with Kana, and photographs in Kana's album document their longstanding friendship. Saki married her high school teacher right after graduation and gave birth to Ichiro soon after. She actively supports and encourages the romantic relationship between her son and Kana, considering their teacher-student dynamic acceptable based on her own experience. Her support includes facilitating their encounters, such as giving Kana a spare key to Ichiro's college apartment. She uses playful tactics, like intentionally getting Kana drunk, to create opportunities for intimacy between them, reflecting her persistent matchmaking efforts. Saki has brown hair and exhibits a cheerful, proactive personality as a parental figure who normalizes unconventional relationships within the series' context.