Mother Tominaga

She is Yuuka's mother who tried to protect her by forcing her to jump out of the widow when their home was forced upon by a drugged craze home invader. She also has a baby whom she hid under the wooden floor, when she was being chased around the house and then stabbed to death by the home invader.

It is suggested that she is also a compulsive hoarder, due to the amount of trash that has accumulated in her home.

(Source: Anime Planet)