According to the statements in the "Kojiki" (Records of Ancient Matters), "Nihonshoki" (Chronicles of Japan), and other history books, the Japanese imperial line has been succeeded by the male bloodline since the first Emperor Jinmu to the hundered and twenty-fifth present Emperor (so-called `unbroken line of Emperors,' however, there are many views regarding the credibility of this theory including the view of Itsue TAKAMURE; that imperial succession was based on the mother-line in ancient times.)
『古事記』、『日本書紀』やその他歴史書の表向きの記載によれば、日本の皇統は初代神武天皇から現在の第125代今上天皇まで男系の血筋のみで続いてきたとされる（いわゆる「万世一系」、ただし信憑性については諸説あり、高群逸枝などの民俗学者は古代が母系制であったことを主張している）。