The religion of Shin is founded on the worship of Kami: nature spirits and the souls of the revered dead. It is closely tied to the belief in Bushido which acts as a form of constant prayer. It is exclusive to the Zhari region due to it's connection with the Spirit World.
The religion was founded shortly after the spirits assisted the people of the Zhari region in freeing themselves from the Yuan-ti as a formal show of respect. During the founding of the Zu Empire, the religion grew into the system of belief it is now.
Shortly before the Spirit War, the religion was largely abandon within the Osijan region due to the enslavement and abuse of spirits that lead to the collapse of the Zu Empire. It was reestablished during the Age of Famine through teachings from the nearby Osaru people that eventually ended the war, however relations between mortals and spirits have never been the same. Spirits rarely appear in the mortal world anymore and few take part in the guidance of mortals.
Shin teaches that everything contains a kami. Kami is generally accepted to describe the innate supernatural force that is above the actions of man, the realm of the sacred, and is inclusive of gods, spirit figures, and human ancestors. All various angels and demons ,among others, of all faiths are considered Kami for the purpose of Shin faith.
The kami reside in all things, but certain places are designated for the interface of people and kami (the material plane and Spirit World): sacred nature and shrines. There are natural places considered to have an unusually sacred spirit about them, and are objects of worship. They are frequently mountains, trees, unusual rocks, rivers, waterfalls, and other natural edifices. In most cases they are on or near a shrine grounds. The shrine is a building built in which to house the kami, with a separation from the material plane through sacred space with defined features based on the age and lineage of the shrine. In each case the object of worship is considered a sacred space inside which the kami spirit actually dwells, being treated with the utmost respect and deference.
Shin is tied with the belief of Bushido. As the religion follows spirits, it is believed that by following this code you honor them as well as your own soul.
It is also believed that anyone who is killed in a dishonorable way become evil Kami.