Karei Hirosaki serves as a Manager at Saiun Dormitory, which belongs to Kazukis dormitory. Despite being a widow, she is known for her kind, calm, warm, and gentle demeanor. Although the show does not provide much information about her, it's evident that she spends most of her time sweeping outside. She consistently wears mourning attire.
While never directly stated in the series, there are strong hints that the man that Karei and Shino once loved is related to Kazuki. The first is that