Shinto religion
This religion started in teh prehistoric times with the veneration of spirits("kami") of the natural world, such as
air,water, fire,etc...
Over time a pantheon of kami seen as progenitors of teh world, including of mankind,emerged. The arrival of buddhism in Japan
in the 6th century had an enormous impact on the shinto religion there, leading to a unique system of correspondence between
foreign buddhist and native shinto gods.
It is therefore not unusual to enounter gods in the current Shinto religion in guise of buddhist priests.