Yuko Shishigami (獅子神優子, Shishigami Yuko) is the mother of Hiro Shishigami.
Yuko is a middle aged woman with short blue navy hair and black eyes.
Yuko divorced from his father since he was in elementary school. She now lives alone with him in a small apartment. They share a room and slept on futons. She also had cancer and wanted her son to continue school and have a good life, she also didn't want to die for his sake.
Yuko committed suicide after learning that her son is a murderer.
- Her name is written with the kanji of gentle (優), and child (子).