Do you understand the true concepts of honour and face, do you know the difference between insulting a gaijin and insulting a native, even if that native is a Blood Dragon? Do you understand how low an outsider should be in your estimation? There's more to it than simple gaijin or not gaijin.
There is no reason for the hatred other than it is ingrained, and has been for more generations than any man can count. They are not human, anymore than a dog is human. But it's more complicated than that, if you really want to understand read up on Edo era Japan. It will have more pointers than I can give and explain properly.
Saint Del is considered a holy healer of diseases of children, but also as a protector of cattle.