This is what I know:
The original Jashinists believed in the respect of all life. To only fight when needed. (Sports being the exeption to this). And to be grateful for all they had. Nowadays Jashinists believe in the understandings of pain. The acceptance and enjoyment of it. The Jashinist's belief in the afterlife is Lord Jashin's plain. There it is believed that those who have harmed others selfishly (this can include Jashinists if they have done so) are punished, and the faithful are rewarded. There is a belief that if you've learned the true meaning of pain, you will be painted white (become albino) and gain immortality. The origins of this belief is unknown.
Do you mean Jainism? I know a little. They can honestly lay claim to being the most non violent religion in the world. More of a 'way of life' than a religion.
Oh... I've never even heard of Jashinism. Is Naruto an anime thing?
Read about the Thuggees of India. Sounds kind of like that.