Shingon Buddhism

Write an essay concerning the Shingon form of Japanese Buddhism:
Who brought the Shingon form of Buddhism to Japan, and under what circumstances?
How did this form of Buddhism become accepted in Japan?
What are its main attributes (rituals, texts, beliefs, practices)?
How, if at all, was this form of Buddhism altered to suit existing Japanese beliefs i.e., Confucian Buddhism and the local Shintoism?