As the eldest daughter of the Kawase household, after the passing of her mother, Satsuki took on the responsibilities as keeper of the house. It was a tough job, with her father and five younger siblings (three sisters and two brothers) to look after! The stress of the work was starting to show, in both her tired face and her dry hands, but she still kept persevering, working hard both at home and in school. She even went so far as to attend an expensive private school (the same school her mother had attended) in spite of the heavier workload she knew it would place on her.
When she met Minoru by chance, however, it was the first time anyone had told her just how tired of life she looked (and she didn't take the comment very well, either). This led their relationship to start off on the wrong foot, but she was surprised to learn later that they had more in common than she had originally believed!