Haruko Uesugi is the mother of twin sons Tatsuya and Kazuya Uesugi. She lives with her husband, Shingo Uesugi, and their children next door to the Asakura family, who run the Minami Kaze coffee shop.

Haruko maintains a consistently carefree and playful personality. She often engages in flirtatious behavior with Shingo, openly showing affection like letting him rest his head in her lap while she cleans his ears, even when their children are present. She is frequently seen smiling, sometimes covering her mouth with her hand as she giggles.

Her interactions with Shingo suggest a happily married relationship marked by mutual teasing and lightheartedness. The couple prioritizes their own enjoyment, sometimes resulting in less attention or support for their sons' needs or activities. This carefree approach to parenting is part of the household dynamic.

Across the series' various adaptations, including films and other official media, Haruko's role and portrayal remain consistent, defined by her cheerful disposition and her relationship with Shingo within the family structure.