Rena Nakano 中野零奈

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.