Short answers, pulled from the story.
The earliest written records using the term Shinto appear in the 8th century texts known as the Kojiki and the Nihon Shoki. These documents were commissioned by ruling elites to legitimize their power rather than to codify a faith.
Kami are supernatural entities that are present everywhere, from the wind and rain to the dead and the living. The number of kami is often described as eight million, a phrase signifying an infinite quantity rather than a literal count.
Kegare refers to pollution or impurity caused by contact with death, disease, blood, or other taboo subjects. Humans are viewed as fundamentally pure, and pollution is corrected through ritual cleansing involving fresh water, salt water, or salt.
It was not until the Meiji era of the 19th century that the government formally separated these practices from Buddhism to create State Shinto. This political intervention effectively invented Shinto as a distinct religion to serve the needs of a modernizing nation.
There are around 100,000 public shrines in Japan, with about 80,000 affiliated with the Association of Shinto Shrines and another 20,000 being unaffiliated. These shrines are found all over the country, from isolated rural areas to dense metropolitan ones.
The niiname-sai, or festival of new rice, is held across many Shinto shrines on the 23rd of November. This autumn festival primarily focuses on thanking the kami for the rice or other harvest.