Tennō kōzoku jitsuroku (天皇皇族実録) = Record of the Emperor and the Imperial Family

Paramount prewar period research materials chronicling the historical traces of successive emperors from Emperor Jinmu to the 121st Emperor Komei, as well as five emperors of the Northern Court, the empresses and consorts, relatives of the emperors, and imperial princesses. Compiled and edited by the Department of the Imperial Household in the pre-war period. This is available through JapanKnowledge platform.