Complex sentence: The Prince was a strong supporter of State Shinto, with Kiichiro Hiranuma he set up the "Shintoist Rites Research Council" to research all ancient Shinto rites and practices.
Split into simpler sentences: The Prince was a strong supporter of State Shinto. With Kiichiro Hiranuma he set up the "Shintoist Rites Research Council" to research all ancient Shinto rites and practices.