At present, the Tennou family is appreciated to have been lasted for 125 generations form the inaugurator of Nihon, the first Tennow Jimmu who achieved the nation-building in the Yayoi era. The key to open the secret of this long-lived and continuous dynasty may be to understand the dual system of religion in a sence that the Tennou has been an officiationg priest and politics in a sence a governor.
