In/Spectre S01E03 - The Rumors of the Steel Lady

Kotoko is asked why a suspect had thrown a dead body into the Guardian's swamp and she starts constructing a story. This ends up being a rather tragic tale about Tanio Aoi filled with love and regret that the Guardian is also shocked to hear. Two years later, random acts of violence were happening in Makurazaka City. The suspect seems to be the ghost of the former idol, Nanase Karin.