Mrs. Tokugawa

Daichi's mother was never mentioned in the anime and appeared only in the manga in the form of flashbacks. She was sick with an unknown illness and appeared in the hospital. Daichi visited her and didn't tell her what was really happening between him and his father. She eventually died of her illness, leaving a very distraught Daichi who was also upset that his father wouldn't even come because of a meeting he was in.