Rena Nakano

She is the biological mother of the Nakano Quintuplets who worked as a teacher. She was a teacher at a high school where she was well-loved and respected by her students. Shimoda was once her student. Rena is known to be a very serious, unsociable, strict, and stern woman, especially when it comes to teaching her students as she would often punish her students with iron-fist sanctions. [Rena was a single mother who raised five children. Before her remarriage with [Maruo Nakano)(https://anilist.co/character/135383), she and the quintuplets were living in poverty like the Uesugi Family, where it is implied that the biological father of the quintuplets ([Mudou)(https://anilist.co/character/157196)) abandoned her and the children. She passed away five years prior to the start of the story on August 14 from an unknown terminal illness and her death was a shock to the quintuplets]