Bansai Ichiyanagi was a prosecutor who served as Chief Prosecutor and Chairman of the Prosecutorial Investigation Committee during his career. He is the father of prosecutor Yumihiko Ichiyanagi. In 2019, he was found to have abused his power for the purpose of various criminal activities and disposing of those who defied him. His actions had far-reaching consequences, especially for the many people affected by the IS-7, DL-6, and SS-5 Incidents.