Rena Nakano

Rena was known to be a very unsociable, serious, strict and severe woman, especially when it came to teaching her students, as she often punished her students with iron-fisted sanctions, but she was also very forgiving and because of that (as well as her appearance), her students adored her and even created a fan club dedicated to worshiping her.
Rena was a single mother raising her five daughters. Before remarrying Maruo Nakano, she and the quintuplets lived in poverty as the Uesugi family, where it is implied that the quintuplets' biological father abandoned her and the girls, thus advising the quintuplets to be careful when choosing men.

She was a teacher at a high school where she was well-liked and respected by her students. Shimoda was once her student and was inspired by Rena to eventually work as a teacher at a high school.