Tokue Kubodera

Ms. Kubodera was Mr. Kubodera's mother, whom he had been caring for due to an illness, but was later murdered by him.

Appearance
Ms. Kubodera was an emaciated old woman with white hair and black eyes.

Background
A cerebral infection had left her comatose and bedridden. She is eventually killed by her son as an apparent attempt to stop the curse, though some say he had simply grown tired of caring for her. She and her son are the "deaths of July."

Plot
She is first mentioned in "Sphere Joint", as the police invistaging her son's suicide entered their home and discovered he had murdered her. Already stressed by the deaths in his class and feeling trapped both by the curse and his bedridden mother, Kubodera killed her. It is unclear how long she'd been dead, but it appears to have been a few days before he arrived in class and killed himself.

Trivia

 * In the manga, Mr. Kubodera killed her by smothering her with a pillow. In the anime, it's unclear how she died.