Sachiko is Satoru's mother and former news announcer. She possesses a sharp eye and is quick to observe any irregularities. She knows about the cold cases of serial kidnapping in her town but decided to keep quiet and ignore it due to her child's growth and safety. However, after having eye contact with the criminal at his latest kidnapping attempt, she was silenced and killed by the kidnapper, which triggered Satoru's 18-year "Revival."