According to this theory, the Emperor Tenmu was virtually the first emperor in Japan. (however, some say the title 'Tenno' (emperor) was first used much earlier, in the era of the Empress Suiko and some say much later, after 701 AD.)
これによれば、天武天皇が事実上の初代天皇だったこととなる（ただし、天皇号をより早く推古期に求める説や、遅く大宝以降とする説もある）。