After the Meiji Restoration, Kokokushikan (emperor-centered historiography which is based on state Shinto) was established in society, it was prohibited to talk about suspicions and scandals in public concerning the Imperial Family, it was prohibited to talk about the theory of Emperor's assassination for a long time, but in July 1940, an obstetrician and gynecologist in Kyoto, Riichiro SAEKI wrote in his essay while he was attending the Kansai Branch of the Japan Society of Medical History, that 'when the Emperor had smallpox, Tomomi IWAKURA ordered his younger sister and the lady-in-waiting, Motoko HORIKAWA, to purposely give poison to the Emperor.'
その後明治維新を過ぎると、世の中には皇国史観が形成され、皇室に関する疑惑やスキャンダルを公言する事はタブーとなり、学術的に孝明天皇の暗殺説を論ずる事は長く封印されたが、1940年（昭和15年）7月、日本医史学会関西支部大会の席上において、京都の婦人科医・佐伯理一郎が「天皇が痘瘡に罹患した機会を捉え、岩倉具視がその妹の女官・堀河紀子を操り、天皇に毒を盛った」旨の論説を発表している。