Shiori Nakagami
She is Shinichirō’s mother; she likes to do what she thinks is best for her son, and tries to look after him. She has been known to read his mail if she deems necessary and often bugs him about things at school, or if his jacket smells. She takes favor over Shinichirō and does not consider Hiromi her child. She often shows hostile attitudes to Hiromi, and this has made her distant from her son. (Wikipedia)
Eventually, she reconciles with Hiromi and tells her that she made up the story about Hiromi being her husband’s child.