The first emperor of Joko existed 317.5 billion years before Christ, even before the Big Bang occurred and the reign of the second emperor of Joko covers thirty-two billion years (although it is said that the name of the emperor of Joko was passed on to his successor and there were about fifty emperors per generation).
ビッグバンさえ起こっていない紀元前3175億年に上古初代天皇が存在し、上古2代天皇の在位が320億年に達している（もっとも上古天皇では天皇の名前は世襲であり、1代数十人だとしているが）。