How is Shintoism a religion?

Answer 1

Shinto is an animistic religion that found its basis on sun-worship and ancestor-worship. Since the Emperor of Japan is thought to have descended from the sun goddess, Amaterasu, he is worshiped as sacred in Shinto lore. There are many gods and goddesses, and many types of spirits, or 'kami' that are respected.

The religion has actually evolved a lot over time. There used to be things like rules for disposing of dolls and shoes and other inanimate objects, because if you disposed of them improperly they would usually sprout spirits and come and kill you or harass you.

Shinto is the basis of a lot of Japan's creation myths, such as the god Izanagi standing on the bridge to heaven, the Amanohashidate (a land bridge that is one of the three most scenic places in Japan) and dipping his spear into the sea; the brine that dripped off of it creating the islands of Japan. (The bridge later fell to earth when he and his wife Izanami were...um...using it...vigorously)

Shinto is still really important in Japan, even if the people aren't crazy religious the way that western cultures understand 'religious.' Even Japanese people who follow other religions participate in Shinto festivals and go to Shinto shrines, simply because it's considered such an intrinsic part of their culture. Most Japanese people are a mixture of Shinto and Buddhist. Shinto rituals mostly deal with life, and Buddhist rituals mostly deal with death, (at least the style of Buddhism popular here) so it mixes well.

I hope this answers your question. If you want more information, Wikipedia is a good thing.