Seishin Funabashi (born 1982) is a Japanese historian specializing in modern and contemporary Japanese history. Born in Ibaraki Prefecture, he completed his doctorate in literature at Nihon University in 2016 and is a researcher at the Institute of Politics and Economy. His work focuses on imperial diplomacy under Emperor Showa, the postwar symbolic-emperor system, and relations between members of the Imperial Family, politics, and society. He was one of the editors of the seven-volume “Shōwa Tennō Haietsuki,” which presents the records kept by Michiji Tajima, the first grand steward of the Imperial Household Agency, of his meetings with the emperor. The series received the planning-category prize at the 77th Mainichi Publishing Culture Awards. Funabashi’s representative book, “Mikasanomiya: Shōwa Tennō Mattei no Kingendaishi,” traces Prince Takahito’s wartime service in Nanjing, his postwar historical scholarship and public interventions, and his role in supporting successive emperors within Japan’s postwar constitutional order.